Journal articles: 'Prolactin'

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Chastel, Olivier, and Hervé Lormée. "Patterns of Prolactin Secretion in Relation to Incubation Failure in a Tropical Seabird, the Red-Footed Booby." Condor 104, no. 4 (November 1, 2002): 873–76. http://dx.doi.org/10.1093/condor/104.4.873.

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Abstract Prolactin levels rapidly drop after breeding failure in several terrestrial bird species, but in penguins prolactin secretion can be maintained well after failure. We measured prolactin secretion in relation to reproductive failure in a tropical seabird, the Red-footed Booby (Sula sula). Incubation failure was recorded in 7 nests (2 accidental losses, 5 desertions). Prolactin titers significantly decreased after incubation failure. In birds that accidentally lost their egg, prolactin titers declined but measurements 12 to 24 hr after failure were still above basal levels. Birds naturally deserting their egg exhibited prolactin titers typical of basal levels 6–24 hr after abandonment. Two birds showed lower prolactin concentration as early as 4–8 days before nest desertion, suggesting that a decline in prolactin levels may precede egg desertion. This study shows that in this tropical seabird, incubation failure results in a rapid cessation of prolactin secretion, as it does for terrestrial birds. Relación entre los Niveles de Prolactina y el Fracaso Reproductivo en un Ave Marina Tropical, Sula sula Resumen. Los niveles de prolactina de varias especies de aves terrestres disminuyen rápidamente después del fracaso reproductivo. Sin embargo, en los pingüinos la secreción de prolactina tiende a mantenerse inalterada después del fracaso reproductivo. Medimos los niveles de prolactina en relación al fracaso reproductivo en un ave marina tropical, Sula sula. Se observaron 7 eventos de fracaso reproductivo (2 pérdidas accidentales de huevos y 5 deserciones de nidos). En general, los niveles de prolactina disminuyeron significativamente después del fracaso reproductivo. En las aves que perdieron accidentalmente sus huevos, los niveles de prolactina disminuyeron, pero las medidas registradas 12 a 24 horas después del fracaso fueron superiores a los niveles basales. Los niveles de prolactina de individuos que espontáneamente abandonaron sus nidos, medidos 6 a 24 horas después del abandono, fueron similares a los niveles basales. Dos individuos presentaron concentraciones de prolactina bajas 4 a 8 días antes del abandono de sus nidos, sugiriendo que una disminución del nivel de prolactina podría preceder el abandono de los nidos. Este estudio demuestra que el fracaso de incubación de esta especie de ave marina tropical conlleva a una rápida cesación de la secreción de prolactina, tal como ha sido observado en las aves terrestres.

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Jerry, D. J., L. C. Griel, J. F. Kavanaugh, and R. S. Kensinger. "Binding and bioactivity of ovine and porcine prolactins in porcine mammary tissue." Journal of Endocrinology 130, no. 1 (July 1991): 43–51. http://dx.doi.org/10.1677/joe.0.1300043.

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ABSTRACT Differential binding of homologous and heterologous prolactin was investigated in porcine mammary tissue. Specific binding of ovine prolactin to porcine mammary membranes or tissue slices was significantly greater than specific binding of the homologous porcine prolactin. Ovine prolactin was also more potent than porcine prolactin in stimulating proliferation of Nb2 cells. In contrast, stimulation of glucose metabolism in porcine mammary explants by porcine prolactin was greater than that by ovine prolactin. Differences in specific binding were probably not due to damage during iodination, as low concentrations of iodinated prolactins were similar to unlabelled prolactins in their abilities to stimulate proliferation of Nb2 cells. Furthermore, electrophoretic analysis of medium from binding reactions suggested that differences in specific binding were not due to proteolytic cleavage of the homologous prolactin into large (> 10 kDa) fragments. These studies suggest that ovine prolactin either binds to sites in addition to the authentic lactogenic receptor in porcine mammary tissue or that a significantly higher affinity of ovine prolactin for the porcine lactogenic receptor has little effect on its biological activity. Journal of Endocrinology (1991) 130, 43–51

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Kim, B. G., and C. L. Brooks. "Isolation and characterization of phosphorylated bovine prolactin." Biochemical Journal 296, no. 1 (November 15, 1993): 41–47. http://dx.doi.org/10.1042/bj2960041.

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Quantitative isolation of bovine prolactin was accomplished by immunoaffinity chromatography using clonal antibody as the stationary ligand. The phosphorylated and non-phosphorylated (native) prolactins contained in the immunopurified preparations were separated by chromatofocusing. Isolates from individual pituitaries revealed that phosphorylated prolactin represented between 20 and 80% of the total prolactin. The stoichiometry of phosphate in phosphorylated prolactin was 1.4:1 when determined by amino acid analysis after preparation of the S-ethylcysteine derivative. One major phosphorylation site, serine-90, and two minor sites, serine-26 and -34, were determined by mapping and sequencing studies. Serine-90 was conserved in prolactins, growth hormones and placental lactogens. Serine-26 and -34 were conserved in prolactins, but were not found in growth hormones or placental lactogens. Absorption spectroscopy of the aromatic amino acid residues indicated that phosphorylation of prolactin was associated with a unique structural conformation.

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Kikuyama, S., T. Yazawa, S. Abe, K. Yamamoto, T. Iwata, K. Hoshi, I. Hasunuma, G. Mosconi, and A. M. Polzonetti-Magni. "Newt prolactin and its involvement in reproduction." Canadian Journal of Physiology and Pharmacology 78, no. 12 (December 1, 2000): 984–93. http://dx.doi.org/10.1139/y00-099.

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The amino acid sequence of newt (Cynops pyrrhogaster) prolactin deduced from the nucleotide sequence of its cDNA showed a relatively high homology with sequences of chicken and sea turtle prolactins as well as with those of anuran prolactins. Cynops prolactin receptor transcripts were detected in various tissues and organs, suggesting that prolactin plays multiple roles in urodeles. Urodele prolactin was purified from the pituitaries of C. pyrrhogaster. Antiserum against this prolactin was used for radioimmunoassay of plasma prolactin and immunoneutralization experiments. Endogenous prolactin was shown to induce migration to water, courtship behavior, and cessation of spermatocytogenesis in the Cynops newt. The hormone was found to be involved in the development of cloacal glands such as the lateral and abdominal glands, growth of the tail and Mauthner neurons, secretion of oviducal jelly, and enhanced synthesis of a female attracting pheromone (sodefrin), and responsiveness of the olfactory epithelium to sodefrin. In most of these cases, prolactin was found to act synergistically or antagonistically with sex steroids. We also discovered that hypersecretion of prolactin in the newts subjected to cold temperature was induced by hypothalamic stimulation rather than release from hypothalamic inhibition.Key words: prolactin, newts, reproduction.

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Sapin, R., E. Le Guyader, A. Agin, and F. Gasser. "Dosages de prolactine Elecsys® : transition Prolactin Prolactin II." Immuno-analyse & Biologie Spécialisée 23, no. 2 (April 2008): 103–8. http://dx.doi.org/10.1016/j.immbio.2007.12.003.

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Scammell, J. G., D. N. Luck, D. L. Valentine, and M. Smith. "Epitope mapping of monoclonal antibodies to bovine prolactin." American Journal of Physiology-Endocrinology and Metabolism 263, no. 3 (September 1, 1992): E520—E525. http://dx.doi.org/10.1152/ajpendo.1992.263.3.e520.

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The epitopes recognized by three monoclonal antibodies generated to sheep prolactin were determined by evaluating their cross-reactivities by immunodot analysis with 14 mutants of bovine prolactin, in which individual amino acids had been deleted or substituted. Mutations were made throughout the molecule and included disruption of the amino-terminal, carboxyl-terminal, and central disulfide loops. Lack of immunoreactivity was taken as an indication that the site of mutation was part of the epitope. Antibody 6F11 reacted with all bovine prolactin mutants tested, except those in which the carboxyl-terminal cysteine (position 199) was substituted by a serine. Antibodies 5G2 and 4C10 reacted with all of the bovine prolactin mutants, except those in which the amino-terminal cysteine (position 4) was substituted by a serine. Western blot analysis of sheep, squirrel monkey, and rat prolactins with the monoclonal antibodies revealed that 5G2 and 4C10 were specific for sheep prolactin, whereas antibody 6F11 cross-reacted with prolactins from all three species. The mitogenic activity of sheep or rat prolactin in the Nb2 bioassay was determined in the presence of the antibodies to determine whether the epitopes were part of the functional domains of these prolactins. The bioactivity of sheep prolactin (0.4 ng/ml) was unaffected by the monoclonal antibodies [0.01-1 microgram immunoglobulin G (IgG)/ml], whereas the bioactivity of rat prolactin (1.25 ng/ml) was inhibited by 6F11 with an apparent 50% inhibitory concentration of 0.25 microgram IgG/ml. These results indicate that monoclonal antibodies 5G2 and 4C10 cross-react with a species-specific region of the amino-terminal disulfide loop of bovine prolactin.(ABSTRACT TRUNCATED AT 250 WORDS)

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Arámburo, C., J. L. Montiel, J. A. Proudman, L. R. Berghman, and C. G. Scanes. "Phosphorylation of prolactin and growth hormone." Journal of Molecular Endocrinology 8, no. 3 (June 1992): 183–91. http://dx.doi.org/10.1677/jme.0.0080183.

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ABSTRACT To determine whether GH and prolactin could be phosphorylated, turkey GH, chicken GH, chicken prolactin and turkey prolactin were incubated in vitro with the catalytic subunit of protein kinase A and [γ-32P]ATP. Phosphorylation was assessed after sodium dodecyl sulphate-polyacrylamide gel electrophoresis, Western blotting and autoradiography. Polyacrylamide electrophoresis showed that both purified native chicken GH and turkey GH were phosphorylated under the conditions employed. However, the glycosylated variant of chicken GH did not appear to be labelled. Chicken prolactin, turkey prolactin and the glycosylated variant of turkey prolactin were all intensely phosphorylated by protein kinase A. Ovine and rat prolactins could also be phosphorylated by protein kinase A. The phosphate content of different native prolactin (turkey, ovine and rat) and GH (ovine and chicken) preparations was also determined and found to be significant. Chicken pituitary cells in primary culture incorporated P in GH- and prolactin-like bands isolated by non-denaturing polyacrylamide gel electrophoresis, and this was stimulated by phorbol myristate acetate. Phosphorylation of GH and prolactin may thus explain some of the charge heterogeneity of these hormones.

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Takahashi, N., K. Yamamoto, and S. Kikuyama. "Cloning of a toad prolactin cDNA: expression of prolactin mRNA in larval and adult pituitaries." Journal of Molecular Endocrinology 11, no. 3 (December 1993): 343–49. http://dx.doi.org/10.1677/jme.0.0110343.

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ABSTRACT A toad (Bufo japonicus) prolactin cDNA was specifically amplified from cDNAs constructed from the total RNA of adenohypophyses, employing the DNA polymerase chain reaction. Sequencing analysis revealed that the cDNA clone thus obtained was 602 bp in length, and encoded the C-terminal 134 amino acid residues of the toad prolactin molecule. The length of the toad prolactin mRNA was estimated to be about 1·0 kb by Northern blot analysis. The partial amino acid sequence deduced from the nucleotide sequence showed the following homologies between toad prolactin and the prolactins of other vertebrates: 69% with man, 80% with chicken, 81% with sea turtle, 91% with bullfrog and 38% with salmon. Using the cDNA as a probe, developmental and seasonal changes in prolactin mRNA levels in the pituitaries of toads were studied. Prolactin mRNA in the pituitary rose as metamorphosis progressed and declined at the end of metamorphosis. During the breeding season the pituitary content of prolactin mRNA was relatively high. This finding suggests that the increases in plasma and pituitary prolactin levels in larvae at metamorphic climax and in adults that remain in or migrate into water, as reported previously, accompany the increase in prolactin synthesis.

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Gabou, L., M. Boisnard, I. Gourdou, H. Jammes, J.-P. Dulor, and J. Djiane. "Cloning of rabbit prolactin cDNA and prolactin gene expression in the rabbit mammary gland." Journal of Molecular Endocrinology 16, no. 1 (February 1996): 27–37. http://dx.doi.org/10.1677/jme.0.0160027.

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ABSTRACT cDNA clones coding for rabbit prolactin were isolated from a pituitary library using a rat prolactin RNA probe. One cDNA contained 873 bases including the entire coding sequence of rabbit prolactin, its signal peptide and the 5′ and 3′ untranslated regions of 44 and 145 nucleotides respectively. The deduced amino acid sequence of the cloned prolactin cDNA presented a 93–78% identity with mink, porcine and human prolactins. The prolactin gene transcription was investigated by RT-PCR analysis in several organs of midlactating New Zealand White rabbits. The ectopic transcription of the prolactin gene was examined in more detail in the mammary gland. A strong PCR signal was detected in the mammary gland of virgin does and was also observed during pregnancy and at the beginning of lactation. This PCR signal was very weak in mid-lactating and absent in post-weaning mammary gland.

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Carnevali, O., G. Mosconi, K. Yamamoto, T. Kobayashi, S. Kikuyama, and A. M. Polzonetti-Magni. "In-vitro effects of mammalian and amphibian prolactins on hepatic vitellogenin synthesis in Rana esculenta." Journal of Endocrinology 137, no. 3 (June 1993): 383–89. http://dx.doi.org/10.1677/joe.0.1370383.

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ABSTRACT Male and female Rana esculenta liver was induced in an in-vitro system by homologous and Rana catesbeiana pituitary to synthesize and release vitellogenin, a lipoglycophosphoprotein precursor of yolk proteins, lipovitellins and phosvitins, in oviparous vertebrates. In the present experiments, the action of prolactin on hepatic vitellogenin synthesis and release was investigated, using ovine prolactin and Rana catesbeiana prolactin. The effects of prolactin on hepatic vitellogenin synthesis displayed different trends related to sex; male liver was found to be more responsive than female liver to both ovine and frog prolactin; moreover, the response to prolactin was dose-related (r = 0·998; P <0·05) in male but not in female liver. In both sexes, a high degree of seasonality in the responsiveness of the liver was found, since the vitellogenin levels induced by prolactin during the winter phase were significantly (P < 0·001) higher than those produced during the summer phase. Thus, there was no significant difference between the action of ovine and frog prolactin on vitellogenin synthesis; in fact, mammalian prolactins are structurally similar with regard to nucleotide and amino acid sequences. The direct action of prolactin on hepatic vitellogenin synthesis in the frog Rana esculenta is discussed, on the basis of the role played by prolactin as an important growth modulatory hormone in fetal and adult tissues. Journal of Endocrinology (1993) 137, 383–389

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Clapp, C., FJ Lopez-Gomez, G. Nava, A. Corbacho, L. Torner, Y. Macotela, Z. Duenas, et al. "Expression of prolactin mRNA and of prolactin-like proteins in endothelial cells: evidence for autocrine effects." Journal of Endocrinology 158, no. 1 (July 1, 1998): 137–44. http://dx.doi.org/10.1677/joe.0.1580137.

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Formation of new capillary blood vessels, termed angiogenesis, is essential for the growth and development of tissues and underlies a variety of diseases including tumor growth. Members of the prolactin hormonal family bind to endothelial cell receptors and have direct effects on cell proliferation, migration and tube formation. Because many angiogenic and antiangiogenic factors are produced by endothelial cells, we investigated whether endothelial cells expressed the prolactin gene. Here we show that bovine brain capillary endothelial cells (BBCEC) in culture express the full-length prolactin messenger RNA, in addition to a novel prolactin transcript, lacking the third exon of the gene. In addition cultures of BBCEC synthesize and secrete prolactin-like immunoreactive proteins with apparent molecular masses of 23, 21 and 14 kDa. The prolactin-like nature of these proteins in supported by the observation that Nb2-cells, a prolactin-responsive cell line, were stimulated to proliferate when co-cultured with endothelial cells and this stimulation was neutralized with prolactin-directed antibodies. Finally, consistent with a possible autocrine effect of endothelial-derived prolactins, polyclonal and monoclonal prolactin antibodies specifically inhibited basal and basis fibroblast growth-factor-stimulated growth of endothelial cells. Taken together, the present findings support the hypothesis of the prolactin gene being expressed in endothelial cells as proteins that could act in an autocrine fashion to regulate cell proliferation.

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Takahashi, N., K. Yoshihama, S. Kikuyama, K. Yamamoto, K. Wakabayashi, and Y. Kato. "Molecular cloning and nucleotide sequence analysis of complementary DNA for bullfrog prolactin." Journal of Molecular Endocrinology 5, no. 3 (December 1990): 281–87. http://dx.doi.org/10.1677/jme.0.0050281.

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ABSTRACT A prolactin cDNA was cloned from a cDNA expression library constructed from total RNA of bullfrog (Rana catesbeiana) adenohypophyses by immunoscreening with antiserum against bullfrog prolactin. The cDNA clone thus obtained contained a 249 bp insert. Using this clone as a probe, plaque hybridizations were performed and two additional clones obtained. These clones had a polyadenylation site different from that of the first obtained clone, suggesting that the 3′-untranslated sequence was heterogeneous in length. The longest clone contained 830 bp, which encoded part of the signal peptide and the entire sequence of mature prolactin. The deduced amino acid sequence was in good accord with that determined by direct protein sequencing of purified bullfrog prolactin. The length of the bullfrog prolactin mRNA was estimated by Northern blot analysis to be about 1·0 kb. Homologies of prolactin nucleotide and amino acid sequences between bullfrog and other vertebrates were 64 and 65% for man, 66 and 68% for pig, 61 and 52% for rat, 69 and 74% for chicken, and 50 and 35% for salmon respectively. Highly conserved regions reported for mammalian prolactins also existed in bullfrog prolactin. Homologies of nucleotide and amino acid sequences between prolactin and GH of bullfrog origin were 49 and 25% respectively. Using the cDNA, the content of prolactin mRNA in the pituitary glands of metamorphosing tadpoles was measured. Prolactin mRNA levels rose at the mid-climax stage, suggesting that the increase in plasma and pituitary prolactin levels known to occur at the climax stage accompanies the increase in prolactin synthesis.

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Soares, M. J., S. K. De, B. A. Foster, J. A. Julian, and S. R. Glasser. "Identification of multiple low molecular weight placental prolactin-like proteins produced by rat trophoblast cells." Journal of Endocrinology 116, no. 1 (January 1988): 101—NP. http://dx.doi.org/10.1677/joe.0.1160101.

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ABSTRACT Rat trophoblast tissue was found to synthesize a number of low molecular weight proteins possessing prolactin-like characteristics. There appear to be at least three proteins that cross-react with antisera to pituitary prolactin. Two of the proteins had a molecular weight of 25 000, similar to ovine pituitary prolactin, and isoelectric points of 6·8 and 7·0. The third immunoreactive protein had a lower molecular weight (23 500), similar in size to human placental lactogen, and a slightly more acidic isoelectric point of 6·75. The molecular weight variants cross-reacted with an antipeptide serum that was generated to a synthetic peptide representing amino acids 150 to 164 of rat placental lactogen-2 (PL-2). Based on this analysis, we consider these proteins to be related to PL-2.Analysis of trophoblast proteins by gel-filtration chromatography resulted in the identification of another trophoblast prolactin. This material eluted earlier than PL-2-related proteins on a gel-filtration column, possessed prolactin-like activity (determined by competition with ovine pituitary prolactin for rabbit mammary gland or rat liver prolactin receptors) but showed limited cross-reactivity with either the antiserum to pituitary prolactin or the antiserum to the PL-2 peptide. We have thus identified multiple low molecular weight trophoblast prolactins, possessing different biochemical and immunological characteristics. J. Endocr. (1988) 116, 101–106

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Weydt, P., M. Gahr, C. Schönfeldt-Lecuona, and B. Connemann. "Hypogonadism and gynecomastia under duloxetine." European Psychiatry 26, S2 (March 2011): 1294. http://dx.doi.org/10.1016/s0924-9338(11)72999-6.

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Introduction/objectives/aimsGynecomastia and hypogonadism can occur during treatment with a range of antidopaminergic drugs and is most likely to a medication induced increase in serum prolactin levels. However there is little evidence for an association between antidepressants and hypogonadism.MethodsWe report the case of a 23 year old male with a 3 year history of bulimia nervosa and recurring depression who had been treated with duloxetine for a period of 6 months during which he developed pronounced bilateral gynocomastia. Since serum prolactine and serum testosterone levels were normal and duloxetin was initially not considered causative, the drug was continued and bilateral gynecomastia was performed. 4 months later the patient again experienced tension and swelling in the breast.ResultsThe endocrinologic exams revealed reduced serum testosterone levels and reduced testicular volume. Body weight was 63 kg, height 176 cm and a neurological exam, including olfactory testing and MR brain imaging was normal. Hypogonadotropic hypogonadism was diagnosed.DiscussionIncreased prolactin levels under antipsychotic medications are not uncommon. Some rare instances of gynecomastia have been reported under fluoxetine and venlafaxine, always associated with increased serum prolactin levels. In the present case the close tempral relationship between initiation of duloxetine and the development of gynecomastia and the recurrence under continued medication and resolution after termination of the medication suggests a possible causal relationship. The normal prolactin levels argue against anvolvement of prolactin in the pathogenesis. We suspect a prolactine independent mechanism.

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Charoenphandhu, Narattaphol, and Nateetip Krishnamra. "Prolactin is an important regulator of intestinal calcium transport." Canadian Journal of Physiology and Pharmacology 85, no. 6 (June 2007): 569–81. http://dx.doi.org/10.1139/y07-041.

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Prolactin has been shown to stimulate intestinal calcium absorption, increase bone turnover, and reduce renal calcium excretion. The small intestine, which is the sole organ supplying new calcium to the body, intensely expresses mRNAs and proteins of prolactin receptors, especially in the duodenum and jejunum, indicating the intestine as a target tissue of prolactin. A number of investigations show that prolactin is able to stimulate the intestinal calcium transport both in vitro and in vivo, whereas bromocriptine, which inhibits pituitary prolactin secretion, antagonizes its actions. In female rats, acute and long-term exposure to high prolactin levels significantly enhances the (i) transcellular active, (ii) solvent drag-induced, and (iii) passive calcium transport occurring in the small intestine. These effects are seen not only in pregnant and lactating animals, but are also observed in non-pregnant and non-lactating animals. Interestingly, young animals are more responsive to prolactin than adults. Prolactin-enhanced calcium absorption gradually diminishes with age, thus suggesting it has an age-dependent mode of action. Although prolactin's effects on calcium absorption are not directly vitamin D-dependent; a certain level of circulating vitamin D may be required for the basal expression of genes related to calcium transport. The aforementioned body of evidence supports the hypothesis that prolactin acts as a regulator of calcium homeostasis by controlling the intestinal calcium absorption. Cellular and molecular signal transductions of prolactin in the enterocytes are largely unknown, however, and still require investigation.

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López-Gómez, F. J., L. Torner, S. Mejía, G. Martínez de la Escalera, and C. Clapp. "Immunoreactive prolactins of the neurohypophyseal system display actions characteristic of prolactin and 16K prolactin." Endocrine 3, no. 8 (August 1995): 573–78. http://dx.doi.org/10.1007/bf02953021.

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Jónsson, Jón Einar, Alan D. Afton, Ray T. Alisauskas, Cynthia K. Bluhm, and Mohamed E. El Halawani. "Ecological and Physiological Factors Affecting Brood Patch Area and Prolactin Levels in Arctic-Nesting Geese." Auk 123, no. 2 (April 1, 2006): 405–18. http://dx.doi.org/10.1093/auk/123.2.405.

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AbstractWe investigated effects of ecological and physiological factors on brood patch area and prolactin levels in free-ranging Lesser Snow Geese (Chen caerulescens caerulescens; hereafter “Snow Geese”) and Ross's Geese (C. rossii). On the basis of the body-size hypothesis, we predicted that the relationships between prolactin levels, brood patch area, and body condition would be stronger in Ross's Geese than in the larger Snow Geese. We found that brood patch area was positively related to clutch volume and inversely related to prolactin levels in Ross's Geese, but not in Snow Geese. Nest size, nest habitat, and first egg date did not affect brood patch area in either species. Prolactin levels increased as incubation progressed in female Snow Geese, but this relationship was not significant in Ross's Geese. Prolactin levels and body condition (as indexed by size-adjusted body mass) were inversely related in Ross's Geese, but not in Snow Geese. Our findings are consistent with the prediction that relationships between prolactin levels, brood patch area, and body condition are relatively stronger in Ross's Geese, because they mobilize endogenous reserves at faster rates than Snow Geese.Factores Ecológicos y Fisiológicos que Afectan el Área del Parche de Incubación y los Niveles de Prolactina en Gansos Nidificantes del Ártico

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Freeman, Marc E., Béla Kanyicska, Anna Lerant, and György Nagy. "Prolactin: Structure, Function, and Regulation of Secretion." Physiological Reviews 80, no. 4 (January 10, 2000): 1523–631. http://dx.doi.org/10.1152/physrev.2000.80.4.1523.

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Prolactin is a protein hormone of the anterior pituitary gland that was originally named for its ability to promote lactation in response to the suckling stimulus of hungry young mammals. We now know that prolactin is not as simple as originally described. Indeed, chemically, prolactin appears in a multiplicity of posttranslational forms ranging from size variants to chemical modifications such as phosphorylation or glycosylation. It is not only synthesized in the pituitary gland, as originally described, but also within the central nervous system, the immune system, the uterus and its associated tissues of conception, and even the mammary gland itself. Moreover, its biological actions are not limited solely to reproduction because it has been shown to control a variety of behaviors and even play a role in homeostasis. Prolactin-releasing stimuli not only include the nursing stimulus, but light, audition, olfaction, and stress can serve a stimulatory role. Finally, although it is well known that dopamine of hypothalamic origin provides inhibitory control over the secretion of prolactin, other factors within the brain, pituitary gland, and peripheral organs have been shown to inhibit or stimulate prolactin secretion as well. It is the purpose of this review to provide a comprehensive survey of our current understanding of prolactin's function and its regulation and to expose some of the controversies still existing.

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Calvo Marín, Javier, Juan Salazar Borbón, and Heylin Montiel Castillo. "Predicción del tamaño de prolactinomas mediante el valor plasmático de prolactina: la propuesta de una fórmula." Revista Colombiana de Endocrinología, Diabetes & Metabolismo 3, no. 1 (March 19, 2017): 35–40. http://dx.doi.org/10.53853/encr.3.1.22.

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Objetivo: Describir la relación existente entre el tamaño tumoral y el nivel de prolactina en pacientes con diagnóstico de prolactinoma manejados en el servicio de endocrinología en un centro de atención especializada de Costa Rica.Diseño: Estudio retrospectivo, observacional y descriptivo con los datos de un único centro.Marco de referencia: En la evaluación del prolactinoma existe consenso en la correlación entre el nivel de prolactina y el tamaño del adenoma, no obstante, son escasos los reportes sobre la magnitud de esta relación y la posibilidad de establecer una ecuación que genere una aproximación del diámetro tumoral.Participantes: Se incluyeron los pacientes con diagnóstico de prolactinoma manejados en el servicio de endocrinología de un centro hospitalario costarricense entre los años 2008 y 2014, en quienes se contaba con una medición de prolactina y un estudio por imágenes que lograra determinar la presencia de un adenoma hipofisario.Intervenciones y mediciones: Para la determinación de prolactina se recurrió al inmunoensayo por electroquimioluminiscencia, y el tamaño tumoral del prolactinoma se definió en estudio por resonancia magnética o tomografía axial computarizada, con un lapso de separación no mayor a seis meses entre ellos.Resultados: Se reclutaron 32 casos de pacientes con prolactinomas. La edad promedio fue de 32,8 años, con un 75% de mujeres y un 56,2% de macroprolactinomas; el tamaño tumoral promedio fue de 15,6 ± 12,3 mm y la mediana de prolactina de 250,5 ng/mL. Se obtuvo un coeficiente de correlación de Pearson de 0,822 (p<0,001), el cual dio base para la creación de dos fórmulas para la predicción del diámetro mayor de la lesión tumoral corregidas por la edad, la primera para prolactinemias menores de 500 ng/mL y otra para valores iguales o mayores a esta cifra.Conclusiones: El presente estudio permitió desarrollar dos ecuaciones mediante las cuales se puede predecir el diámetro mayor tumoral aproximado a partir del valor inicial hormonal.Abstract Introduction: In the clinical evaluation of patients with prolactinomas, there is a consensus on the literature regarding the correlation between prolactin levels and tumor size; however, there are few reports that detail about the magnitude of this relationship and the possibility of establishing an equation that may estimate the adenoma diameter. Material and methods: We conducted a retrospective, observational and descriptive study with data from a single center, which intended to verify the relationship between tumor size and prolactinemia. All of the included patients had measurements for prolactin blood levels and pituitary imaging with at least one diameter measurement of the adenoma.Measurements and interventions: prolactin blood levels were determined by electrochemicaluminiscense immunoassay, and the size of the adenoma was defined by magnetic resonance imaging or computerized axial tomography scan, each study taken within a maximum of 6 months. Results: Thirty-two cases of patients with prolactinomas were assessed. The average age of the patients was of 32,8 ± 13,1 years, 75% were women and 56,2% were diagnosed with a macroprolactinoma. Mean tumor size was of 15,6 ± 12,3 mm and the median of prolactin level was 250,5 ng/mL. We report a Pearson’s correlation coefficient of 0,82 (p<0,001), showing a strong positive linear association between the prolactinemia and the tumor size. Through multiple linear regression analysis, we obtained two equations that allowed the prediction of the adenoma diameter given the prolactin level, adjusted by age. Conclusion: We developed two equations that allowed us to estimate the largest tumoral diameter given the prolactin blood levels.

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Saade, G., D. R. London, M. R. A. Lalloz, and R. N. Clayton. "Regulation of LH subunit and prolactin mRNA by gonadal hormones in mice." Journal of Molecular Endocrinology 2, no. 3 (May 1989): 213–24. http://dx.doi.org/10.1677/jme.0.0020213.

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ABSTRACT The effect of castration and gonadal steroid replacement on the concentrations of LH-β and α subunit and prolactin mRNA was examined in mice. Mouse LH-β, α and prolactin mRNAs were approximately 0·8, 0·7 and 1·1 kb in size respectively. After ovariectomy, LH-β mRNA levels increased 2- to 2·5-fold, while α mRNA levels increased 2·5-fold 6 and 10 days after ovariectomy. Serum LH rose after 2 days to reach six times control values at 10 days. Pituitary LH content doubled by 8 days after ovariectomy. Prolactin mRNA levels decreased to 50–60% of control at 3, 6, 8 and 10 days after ovariectomy and parallelled the fall in serum prolaction. Pituitary prolactin content fell more slowly, to 50% of intact control values by 10 days. The increase in both LH-β and α subunit mRNA, and decrease in prolactin mRNA, and serum and pituitary hormone changes, after ovariectomy were prevented by oestradiol or oestradiol plus progesterone replacement. Levels of LH-β mRNA increased more quickly in male than in female mice, theearliest change being seen 24 h after orchidectomy. Maximum values (two- to threefold) were found on day 6 after orchidectomy. Concentrations of α mRNA increased by 12 h to between 2 and 2·5 times control from 3 to 10 days after orchidectomy. Serum LH doubled by 12 h and was three to five times greater than control values up to 10 days. Pituitary LH content fell by 48 h before gradually increasing to intact values after 10 days. Prolactin mRNA levels decreased progressively from 2 days after orchidectomy, and this decrease was preceded by a fall in serum and pituitary prolactin which remained low throughout the experiment. Testosterone treatment attenuated the rise in α mRNA, prevented the rise in LH-β mRNA and serum LH and partially restored the decrease in prolactin mRNA seen after orchidectomy. We conclude that in mice, as in rats and ewes, both LH-β and α subunit mRNAs are negatively regulated by gonadal steroids, whereas prolactin mRNA is positively regulated, although there are temporal differences in patterns of mRNA responses between males and females. By comparison with female rats the rise in LH-β mRNA after ovariectomy was slower in mice. Moreover, the discordant changes in pituitary LH content and LH subunit mRNAs seen in mice after castration were not observed in rats. Furthermore, pituitary prolactin and prolactin mRNA do not fall after orchidectomy of rats. The modest (50%) increase of LH-β mRNA after castration of mice suggests that an increase in mRNA is not necessarily required for increased LH production.

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Farnsworth, Wells E. "Prolactin." Journal of Urology 133, no. 3 (March 1985): 488. http://dx.doi.org/10.1016/s0022-5347(17)49038-0.

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Vonderhaar, Barbara K. "Prolactin." Pharmacology & Therapeutics 79, no. 2 (August 1998): 169–78. http://dx.doi.org/10.1016/s0163-7258(98)00017-5.

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Anderson, Greg M., David C. Kieser, Frederick J. Steyn, and David R. Grattan. "Hypothalamic Prolactin Receptor Messenger Ribonucleic Acid Levels, Prolactin Signaling, and Hyperprolactinemic Inhibition of Pulsatile Luteinizing Hormone Secretion Are Dependent on Estradiol." Endocrinology 149, no. 4 (December 27, 2007): 1562–70. http://dx.doi.org/10.1210/en.2007-0867.

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Hyperprolactinemia can reduce fertility and libido. Although central prolactin actions are thought to contribute to this, the mechanisms are poorly understood. We first tested whether chronic hyperprolactinemia inhibited two neuroendocrine parameters necessary for female fertility: pulsatile LH secretion and the estrogen-induced LH surge. Chronic hyperprolactinemia induced by the dopamine antagonist sulpiride caused a 40% reduction LH pulse frequency in ovariectomized rats, but only in the presence of chronic low levels of estradiol. Sulpiride did not affect the magnitude of a steroid-induced LH surge or the percentage of GnRH neurons activated during the surge. Estradiol is known to influence expression of the long form of prolactin receptors (PRL-R) and components of prolactin’s signaling pathway. To test the hypothesis that estrogen increases PRL-R expression and sensitivity to prolactin, we next demonstrated that estradiol greatly augments prolactin-induced STAT5 activation. Lastly, we measured PRL-R and suppressor of cytokine signaling (SOCS-1 and -3 and CIS, which reflect the level of prolactin signaling) mRNAs in response to sulpiride and estradiol. Sulpiride induced only SOCS-1 in the medial preoptic area, where GnRH neurons are regulated, but in the arcuate nucleus and choroid plexus, PRL-R, SOCS-3, and CIS mRNA levels were also induced. Estradiol enhanced these effects on SOCS-3 and CIS. Interestingly, estradiol also induced PRL-R, SOCS-3, and CIS mRNA levels independently. These data show that GnRH pulse frequency is inhibited by chronic hyperprolactinemia in a steroid-dependent manner. They also provide evidence for estradiol-dependent and brain region-specific regulation of PRL-R expression and signaling responses by prolactin.

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Utama, Fransiscus E., Thai H. Tran, Amy Ryder, Matthew J. LeBaron, Albert F. Parlow, and Hallgeir Rui. "Insensitivity of Human Prolactin Receptors to Nonhuman Prolactins: Relevance for Experimental Modeling of Prolactin Receptor-Expressing Human Cells." Endocrinology 150, no. 4 (November 20, 2008): 1782–90. http://dx.doi.org/10.1210/en.2008-1057.

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Hanks, M. C., J. A. Alonzi, P. J. Sharp, and H. M. Sang. "Molecular cloning and sequence analysis of putative chicken prolactin cDNA." Journal of Molecular Endocrinology 2, no. 1 (January 1989): 21–30. http://dx.doi.org/10.1677/jme.0.0020021.

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ABSTRACT A cDNA library was prepared from mRNA isolated from anterior pituitary glands of incubating bantam hens, in which prolactin mRNA levels were predicted to be very high. Nine clones, representing abundant mRNA species, were identified and shown to contain homologous sequences. Two clones, of 871 bp and 580 bp, were analysed by DNA sequencing. The shorter clone was found to be a truncated cDNA product but otherwise identical to the longer clone. The 871 bp cDNA, PRL101, contains an open reading frame capable of encoding a polypeptide of 229 amino acids. This putative polypeptide has a high degree of homology to mammalian prolactins (approximately 70%), strongly suggesting that PRL101 encodes chicken preprolactin. The protein was predicted to have a 30 amino acid signal sequence which would be cleaved off to give a mature protein of 199 amino acids. The peptide sequence also had a 26% homology to chicken growth hormone, which is related to prolactin. This similarity confirms the conclusion that PRL101 is a chicken prolactin cDNA clone. An abundant mRNA of approximately 880 b was detected in poly(A)+ RNA from pituitary glands probed with PRL101. Analysis of chicken genomic DNA showed that there is one copy of the prolactin gene in the genome. PRL101 hybridized strongly to genomic DNA from closely related galliforms (quail and turkey) and less strongly to DNA from more distantly related species (duck and ring dove).

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26

Safitri, Erma. "METODE PEMBUATAN ANTIPROLAKTIN PADA HEWAN COBA KAMBING LOKAL SEBAGAI PENGHAMBAT PROSES RONTOK BULU PADA AYAM ARAB PETELUR." Berkala Penelitian Hayati 11, no. 1 (December 31, 2005): 49–54. http://dx.doi.org/10.23869/bphjbr.11.1.20058.

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Anti-prolactin has a specific activity against prolactin. It neutralizes prolactin action in circulation. The effect of such neutralization is the inhibition of feather fall off process, so that hens may be able to produce eggs again. Anti-prolactin can be produced by injecting prolactin isolate from blood serum of arabic hens in feather fall off-phase into local goat. Prolactin isolate was immunized to local goat to produce anti-prolactin. Six local goats were divided into 2 groups. The first group comprised 1 goat immunized with PBS, and the second one was immunized with prolactin isolate in CFA and subjected to booster with prolactin isolate in IFA twice. The formation of anti-prolactin and the highest titer was detected using indirect ELISA. The results of this study showed that (1) Anti-prolactin could be produced in goat from the prolactin isolate of feather fall off-phase arabic hens blood serum; (2). The first emergence of Antiprolactin was at the first bleeding after immunization of prolactin isolate in CFA and first booster in IFA. The highest titer was found at eleventh bleeding after the third booster with prolactin isolate in IFA.

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Anderson, Greg M., David R. Grattan, Willemijn van den Ancker, and Robert S. Bridges. "Reproductive Experience Increases Prolactin Responsiveness in the Medial Preoptic Area and Arcuate Nucleus of Female Rats." Endocrinology 147, no. 10 (October 1, 2006): 4688–94. http://dx.doi.org/10.1210/en.2006-0600.

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The experience of pregnancy plus lactation produces long-term enhancements in maternal behavior as well as reduced secretion of prolactin, a key hormone for the initial establishment of maternal care. Given that prolactin acts centrally to induce maternal care as well as regulate its own secretion, we tested whether prolactin receptors in brain regions known to regulate behavioral and neuroendocrine processes were up-regulated and more responsive to prolactin in reproductively experienced females. Diestrous primiparous (8 wk after weaning) and age-matched virgin rats were treated with 250 μg ovine prolactin sc or vehicle and the brains collected 2 h later for measurement of mRNA for genes involved in prolactin signaling. Reproductively experienced rats had lower serum prolactin concentrations, compared with virgin rats, suggesting enhanced prolactin feedback on the arcuate neurons regulating prolactin secretion. In the medial preoptic area and arcuate nucleus (regions involved in regulating maternal behavior and prolactin secretion, respectively), the level of long-form prolactin receptor mRNA was higher in primiparous rats, and prolactin treatment induced a further increase in receptor expression in these animals. In the same regions, suppressors of cytokine signaling-1 and -3 mRNA levels were also markedly increased after prolactin treatment in reproductively experienced but not virgin rats. These results support the idea that reproductive experience increases central prolactin responsiveness. The induction of prolactin receptors and enhanced prolactin responsiveness as a result of pregnancy and lactation may help account for the retention of maternal behavior and shifts in prolactin secretion in reproductively experienced females.

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Grattan, David R., and Raphael E. Szawka. "Kisspeptin and Prolactin." Seminars in Reproductive Medicine 37, no. 02 (March 2019): 093–104. http://dx.doi.org/10.1055/s-0039-3400956.

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AbstractThe relationship between elevated prolactin and infertility has been known for a long time, but the specific mechanism by which prolactin inhibited reproduction had been uncertain. The discovery of kisspeptin has provided novel insights into how prolactin might cause infertility, with extensive evidence that elevated prolactin inhibits secretion of kisspeptin, resulting in hypogonadotropic hypogonadism, and infertility. More recent data suggest that a converse relationship might also exist, with evidence that kisspeptin influences prolactin secretion. This brief review will examine the relationship between kisspeptin and prolactin from each of these two perspectives: the well-characterized inhibitory effect of prolactin on kisspeptin neurons and the more recent concept that kisspeptin neurons are involved in the control of prolactin secretion.

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Champier, J., B. Claustrat, C. Harthe, P. Chevallier, and J. Trouillas. "Concanavalin-A-bound and -unbound prolactin in normal and hyperprolactinaemic rats." Journal of Endocrinology 134, no. 1 (July 1992): 27–32. http://dx.doi.org/10.1677/joe.0.1340027.

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ABSTRACT Concanavalin-A (Con-A)-bound and -unbound forms of prolactin were studied in female Wistar–Furth rats, both normal and with hyperprolactinaemia induced by treatment with oestrogen or a prolactinoma graft. In normal rats, Con-A-bound prolactin was the major circulating form (more than 50%) and a minor pituitary component (less than 10%), essentially as 25 kDa prolactin. In oestrogen-treated rats, plasma prolactin levels were 100-fold higher and pituitary weight was fivefold higher than in the controls, but total pituitary prolactin content was unmodified. Under oestrogen, Con-A-bound prolactin represented about one-third of the total hormone levels in the plasma and less than 10% in the pituitary. In the pituitary, bound prolactin was found essentially as 25 kDa and unbound prolactin as 22, 30 and 40–45 kDa. A similar increase in plasma prolactin levels was induced 6 months after the graft of a prolactinoma. Pituitary weights and total pituitary prolactin contents were slightly decreased. Plasma and pituitary Con-A-bound prolactin levels were similar to those observed in oestrogen-treated rats. On the other hand, unbound prolactin was only present as a 22 kDa monomer. In the tumour, Con-A-bound prolactin (essentially as 25 kDa prolactin) represented one-third of the total hormone level and unbound prolactin was composed of the 22 and 45 kDa forms, this latter form being partially transformed into 22 kDa by heating. As Con-A-bound prolactin was previously characterized as glycosylated prolactin, these data suggest that glycosylated prolactin is present in the plasma of the normal rat as a major circulating form, unglycosylated 40–45 kDa is only present when the rate of the prolactin synthesis is high (in the pituitary of oestrogen-treated rats and in the tumour of grafted rats); this result supporting the hypothesis of a precursor product relationship between dimeric and monomeric prolactin. The manners in which prolactin is synthetized are not comparable in normal and tumour cells, percentages of glycosylated prolactin being different in normal pituitary and prolactinoma. Journal of Endocrinology (1992) 134, 27–32

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30

Greenspan, S. L., A. Klibanski, J. W. Rowe, and D. Elahi. "Age alters pulsatile prolactin release: influence of dopaminergic inhibition." American Journal of Physiology-Endocrinology and Metabolism 258, no. 5 (May 1, 1990): E799—E804. http://dx.doi.org/10.1152/ajpendo.1990.258.5.e799.

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To determine the effect of age on pulsatile prolactin secretion, we examined prolactin pulse characteristics by cluster analysis in healthy young and old male subjects during the day and night. Pulsatile prolactin secretion was identified in all subjects during the day and night, and prolactin pulse frequency remains stable with age. Younger subjects had a significantly higher prolactin pulse amplitude, area, and peak interval during the night compared with older subjects. In contrast, daytime prolactin pulse characteristics were similar in young and old subjects. Because the major neuroregulator of prolactin is dopamine and because normal aging has been reported to be associated with reductions in hypothalamic dopamine content and effect, we determined whether the mechanism of altered day-night prolactin pulsatile secretion was due to changes in dopaminergic tone. We examined endogenous prolactin secretion after administration of the dopamine antagonist metoclopramide. Metoclopramide significantly increased mean serum prolactin concentration and prolactin pulse height and amplitude in all subjects during the day and night. However, net prolactin pulse amplitude after metoclopramide stimulation at night was significantly higher in older subjects compared with younger subjects. We conclude that prolactin pulse amplitude is blunted in elderly men at night and that daytime pulsatile prolactin secretion is unaltered by age in normal men. The mechanism for this alteration of nighttime prolactin pulsatile secretion in elderly men may be due to age-associated changes in dopaminergic regulation.

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31

Martin, Niamh. "Prolactin disorders." Medicine 49, no. 8 (August 2021): 492–94. http://dx.doi.org/10.1016/j.mpmed.2021.05.008.

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Horseman, Nelson D., and Karen A. Gregerson. "Prolactin actions." Journal of Molecular Endocrinology 52, no. 1 (October 15, 2013): R95—R106. http://dx.doi.org/10.1530/jme-13-0220.

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Molecular genetics and other contemporary approaches have contributed to a better understanding of prolactin (PRL) actions at the cellular and organismal levels. In this review, several advances in knowledge of PRL actions are highlighted. Special emphasis is paid to areas of progress with consequences for understanding of human PRL actions. The impacts of these advances on future research priorities are analyzed.

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Todd, Jeannie F. "Prolactin disorders." Medicine 33, no. 11 (November 2005): 16–17. http://dx.doi.org/10.1383/medc.2005.33.11.16.

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Bevan, John S. "Prolactin Disorders." Medicine 29, no. 11 (November 2001): 10–14. http://dx.doi.org/10.1383/medc.29.11.10.28431.

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Yazigi, Ricardo A., Carlos H. Quintero, and Wael A. Salameh. "Prolactin disorders." Fertility and Sterility 67, no. 2 (February 1997): 215–25. http://dx.doi.org/10.1016/s0015-0282(97)81900-0.

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Martin, Niamh. "Prolactin disorders." Medicine 37, no. 8 (August 2009): 411–13. http://dx.doi.org/10.1016/j.mpmed.2009.05.003.

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37

Martin, Niamh. "Prolactin disorders." Medicine 41, no. 9 (September 2013): 516–18. http://dx.doi.org/10.1016/j.mpmed.2013.06.005.

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Martin, Niamh. "Prolactin disorders." Medicine 45, no. 8 (August 2017): 484–87. http://dx.doi.org/10.1016/j.mpmed.2017.05.003.

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39

Onwubalili, Ndidiamaka, and Jacquelyn S. Loughlin. "Prolactin Disorders." Postgraduate Obstetrics & Gynecology 33, no. 8 (April 2013): 1–7. http://dx.doi.org/10.1097/01.pgo.0000430267.55532.36.

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40

&NA;. "Prolactin Disorders." Postgraduate Obstetrics & Gynecology 33, no. 8 (April 2013): 8. http://dx.doi.org/10.1097/01.pgo.0000430268.63156.8b.

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41

Sinha, Yagya N. "Prolactin variants." Trends in Endocrinology & Metabolism 3, no. 3 (April 1992): 100–106. http://dx.doi.org/10.1016/1043-2760(92)90021-r.

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Shin, Seon H., and John S. Elce. "The effects of dopamine on prolactin mRNA levels in rat pituitary cells in culture." Canadian Journal of Physiology and Pharmacology 70, no. 3 (March 1, 1992): 403–7. http://dx.doi.org/10.1139/y92-050.

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Dopamine is known to be the prolactin-release inhibiting factor, but the effects of dopamine itself on regulation of prolactin messenger RNA have been little studied because of the instability of dopamine. We have compared the effects of dopamine and bromocriptine on the levels of prolactin mRNA and on the rates of synthesis, storage, and release of prolactin in primary cultured rat pituitary cells. The cells were incubated for 72 h with no secretagogue (control group) or in the presence of either dopamine (10 μmol/L) plus ascorbic acid (100 μmol/L) or bromocriptine (0.1 μmol/L). Prolactin mRNA was measured in cell extracts by means of slot blots, and newly synthesized prolactin was measured in similar incubations by the addition of [3H]leucine, followed by gel electrophoresis. The levels of total prolactin were measured by radioimmunoassay. Prolactin mRNA was reduced to 78 ± 9% (mean ± SEM) of control levels in bromocriptine-treated cells and to 59 ± 7% in dopamine-treated cells, demonstrating that dopamine stabilized by ascorbic acid was able to reduce the levels of prolactin mRNA in rat pituitary cells in culture. Dopamine may act at sites in addition to the dopaminergic D2 receptor, since the level of prolactin mRNA was reduced more by a supramaximal dose of dopamine than by a supramaximal dose of bromocriptine. The results of the [3H]prolactin and prolactin measurements suggested that availability of mRNA was not a major factor in controlling the rate of prolactin synthesis.Key words: prolactin, dopamine, bromocriptine, prolactin mRNA, prolactin biosynthesis, cell culture.

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Tansey, M. J., and J. A. Schlechte. "Pituitary production of prolactin and prolactin-suppressing drugs." Lupus 10, no. 10 (October 2001): 660–64. http://dx.doi.org/10.1191/096120301717164886.

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Neidhart, M., R. E. Gay, and S. Gay. "Prolactin and prolactin-like polypeptides in rheumatoid arthritis." Biomedicine & Pharmacotherapy 53, no. 5-6 (June 1999): 218–22. http://dx.doi.org/10.1016/s0753-3322(99)80091-2.

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Huang, KuangTzu, Eric Ueda, YenHao Chen, and Ameae M. Walker. "Paradigm-Shifters: Phosphorylated Prolactin and Short Prolactin Receptors." Journal of Mammary Gland Biology and Neoplasia 13, no. 1 (January 25, 2008): 69–79. http://dx.doi.org/10.1007/s10911-008-9072-x.

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Levin, Gabriel, and Amihai Rottenstreich. "Prolactin, prolactin disorders, and dopamine agonists during pregnancy." Hormones 18, no. 2 (October 19, 2018): 137–39. http://dx.doi.org/10.1007/s42000-018-0071-z.

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Rush, Stephen, Bernardine Donahue, Paul Cooper, Christopher Lee, Mark Persky, and Joseph Newall. "Prolactin Reduction after Combined Therapy for Prolactin Macroadenomas." Neurosurgery 28, no. 4 (April 1, 1991): 502–5. http://dx.doi.org/10.1227/00006123-199104000-00003.

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Abstract The ability of surgery or bromocriptine to produce endocrine control of a prolactin macroadenoma decreases as the prolactin level increases. Guidelines for the use of multimodality therapy have not been developed for tumors associated with markedly elevated prolactin levels. We reviewed the records of 21 patients with prolactin levels >200 ng/ml treated by transsphenoidal surgery and postoperative radiotherapy with or without a dopamine agonist. Values before and after treatment were available for 19 patients (13 men and 6 women);. The mean basal prolactin level before treatment for the entire group was 2410 ng/ml. Surgery and radiotherapy resulted in a 90% reduction and serum prolactin levels within normal limits in 0 of 7 patients, versus the combination of surgery, radiotherapy, and dopamine agonist, which resulted in a 99.5% reduction and values within the normal range in 12 of 12 patients. Spontaneous physiological improvement was not often observed. One woman and two men were able subsequently to have children. A plan for these patients is discussed.

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WOOD, RICHARD L., JIAN ZHANG, ZUO MING HUANG, J. PETER GIEROW, JOEL E. SCHECHTER, AUSTIN K. MIRCHEFF, and DWIGHT W. WARREN. "Prolactin and Prolactin Receptors in the Lacrimal Gland." Experimental Eye Research 69, no. 2 (August 1999): 213–26. http://dx.doi.org/10.1006/exer.1999.0690.

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Almazrouei, Raya, Shamaila Zaman, Florian Wernig, and Karim Meeran. "Utility of Cannulated Prolactin to Exclude Stress Hyperprolactinemia in Patients with Persistent Mild Hyperprolactinemia." Clinical Medicine Insights: Endocrinology and Diabetes 14 (January 2021): 117955142110252. http://dx.doi.org/10.1177/11795514211025276.

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Background: Stress-induced hyperprolactinemia can be difficult to differentiate from true hyperprolactinema and may result in patients having unnecessary investigations and imaging. We report the results of cannulated prolactin tests with serial prolactin measurements from an indwelling catheter to differentiate true from stress-induced hyperprolactinemia in patients with persistently mildly elevated prolactin levels in both referral and repeat samples. Methods: Data were collected for 42 patients who had a cannulated prolactin test between January 2017 and May 2018. After cannula insertion, prolactin was measured at 0, 60, and 120 minutes. Normalization is defined as a decline in prolactin to gender-defined normal ranges. Results: The mean age was 33.8 years ( SD ± 9.9), and 37 (88%) were female. Menstrual irregularities were the main presenting symptom in 28.57% of the patients. Prolactin normalized in 12 (28.6%) patients of whom cannulated prolactin test was done. Repeat random prolactin levels were significantly higher in patients whose prolactin did not normalize during the cannulated prolactin test. MRI of the pituitary gland showed an abnormality in 23 out of 28 (82%) patients who did not normalize prolactin, a microadenoma in the majority of patients (18 patients). Conclusion: The cannulated prolactin test was useful in excluding true hyperprolactinemia in 28.6% of patients with previously confirmed mildly elevated random prolactin on two occasions, thus avoiding over-diagnosis and unnecessary imaging.

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Wu, W.-X., J. Brooks, A. F. Glasier, and A. S. McNeilly. "The relationship between decidualization and prolactin mRNA and production at different stages of human pregnancy." Journal of Molecular Endocrinology 14, no. 2 (April 1995): 255–61. http://dx.doi.org/10.1677/jme.0.0140255.

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ABSTRACT Within the human utero-placental unit only decidualized stromal cells express mRNA for prolactin. However, it is not clear if the level of prolactin production is related to the number of decidualized cells or the capacity of individual decidual cells to synthesize prolactin, either or both of which parameters may change during pregnancy. In the present study, prolactin production at different stages of human pregnancy was examined using quantitative in situ hybridization to assess decidual prolactin mRNA abundance, immunocytochemistry to examine the prolactin content inside decidual cells and RIA to measure decidual prolactin output into amniotic fluid. Throughout pregnancy the proportion of stromal cells showing positive immunostaining and mRNA for prolactin increased. There was a parallel increase in decidual cell size which was correlated with an increase in prolactin gene expression and intensity of immuno-staining for prolactin in individual decidual cells. These changes in decidual cells were consistent with the changes in the concentration of prolactin in amniotic fluid. These results suggest that there is a close link between the level of prolactin gene expression and production of prolactin by individual decidual cells, which in turn is directly related to the process of decidualization that continues throughout human pregnancy.

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Journal articles on the topic 'Prolactin'

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