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. 1975 Apr;51(594):231–235. doi: 10.1136/pgmj.51.594.231

Lactation and the physiology of prolactin secretion

A S McNeilly
PMCID: PMC2495950  PMID: 1197152

Abstract

Prolactin in man appears to form an essential part of the complex of hormones necessary for milk secretion and lactation. Levels of prolactin during pregnancy gradually increase towards term, and remain elevated for up to 6 weeks post partum. The lactogenic effects of prolactin appear to be blocked at the mammary gland by the elevated levels of fetoplacental steroids secreted during pregnancy. The immediate decline in steroid levels at delivery removes this block to prolactin and milk secretion ensues.

The amenorrhoea associated with both puerperal lactation and galactorrhoea appears to reflect failure of cyclical discharge of gonadotrophins and anovulation. This appears to be due to peripheral inhibition of steroidogenesis by the elevated levels of prolactin associated with these situations. No consistent changes in circulating levels of prolactin occur during the menstrual cycle, but changes in prolactin levels within the follicular fluid of the developing ovarian follicle indicate a specific and permissive role of prolactin in steroidogenesis.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Besser G. M., Parke L., Edwards C. R., Forsyth I. A., McNeilly A. S. Galactorrhoea: successful treatment with reduction of plasma prolactin levels by brom-ergocryptine. Br Med J. 1972 Sep 16;3(5828):669–672. doi: 10.1136/bmj.3.5828.669. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bowers C. Y., Friesen H. G., Folkers K. Further evidence that TRH is also a physiological regulator of PRL secretion in man. Biochem Biophys Res Commun. 1973 Apr 2;51(3):512–521. doi: 10.1016/0006-291x(73)91344-2. [DOI] [PubMed] [Google Scholar]
  3. Del Pozo E., Del Re R. B., Varga L., Friesen H. The inhibition of prolactin secretion in man by CB-154 (2-Br-alpha-ergocryptine). J Clin Endocrinol Metab. 1972 Nov;35(5):768–771. doi: 10.1210/jcem-35-5-768. [DOI] [PubMed] [Google Scholar]
  4. Ehara Y., Siler T., VandenBerg G., Sinha Y. N., Yen S. S. Circulating prolactin levels during the menstrual cycle: episodic release and diurnal variation. Am J Obstet Gynecol. 1973 Dec 1;117(7):962–970. doi: 10.1016/0002-9378(73)90069-0. [DOI] [PubMed] [Google Scholar]
  5. Frantz A. G., Kleinberg D. L., Noel G. L. Studies on prolactin in man. Recent Prog Horm Res. 1972;28:527–590. [PubMed] [Google Scholar]
  6. Gautvik K. M., Weintraub B. D., Graeber C. T., Maloof F., Zuckerman J. E., Tashjian A. H., Jr Serum prolactin and TSH: effects of nursing and pyroGlu-His-ProNH2 administration in postpartum women. J Clin Endocrinol Metab. 1973 Jul;37(1):135–139. doi: 10.1210/jcem-37-1-135. [DOI] [PubMed] [Google Scholar]
  7. Hwang P., Guyda H., Friesen H. A radioimmunoassay for human prolactin. Proc Natl Acad Sci U S A. 1971 Aug;68(8):1902–1906. doi: 10.1073/pnas.68.8.1902. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Jaffe R. B., Yuen B. H., Keye W. R., Jr, Midgley A. R., Jr Physiologic and pathologic profiles of circulating human prolactin. Am J Obstet Gynecol. 1973 Nov 15;117(6):757–773. doi: 10.1016/0002-9378(73)90491-2. [DOI] [PubMed] [Google Scholar]
  9. Kolodny R. C., Jacobs L. S., Daughaday W. H. Mammary stimulation causes prolactin secretion in non-lactating women. Nature. 1972 Aug 4;238(5362):284–286. doi: 10.1038/238284a0. [DOI] [PubMed] [Google Scholar]
  10. McNatty K. P., Sawers R. S., McNeilly A. S. A possible role for prolactin in control of steroid secretion by the human Graafian follicle. Nature. 1974 Aug 23;250(5468):653–655. doi: 10.1038/250653a0. [DOI] [PubMed] [Google Scholar]
  11. McNeilly A. S., Hagen C. Prolactin, TSH, LH and FSH responses to a combined LHRH-TRH test at different stages of the menstrual cycle. Clin Endocrinol (Oxf) 1974 Oct;3(4):427–435. doi: 10.1111/j.1365-2265.1974.tb02813.x. [DOI] [PubMed] [Google Scholar]
  12. McNeilly A. S. Radioimmunoassay of human prolactin. Proc R Soc Med. 1973 Sep;66(9):863–864. [PMC free article] [PubMed] [Google Scholar]
  13. McNeilly A. S., Sturdy J., Evans D. G., Chard T. Short-term variation in blood levels of prolactin, luteinizing hormone and follicle-stimulating hormone in normal men throughout the day. J Endocrinol. 1974 May;61(2):301–302. doi: 10.1677/joe.0.0610301. [DOI] [PubMed] [Google Scholar]
  14. Mortimer C. H., Besser G. M., McNeilly A. S., Tunbridge W. M., Gomez-Pan A., Hall R. Interaction between secretion of the gonadotrophins, prolactin, growth hormone, thyrotrophin and corticosteroids in man: the effects of LH FSH-RH, TRH and hypoglycaemia alone and in combination. Clin Endocrinol (Oxf) 1973 Oct;2(4):317–326. doi: 10.1111/j.1365-2265.1973.tb01717.x. [DOI] [PubMed] [Google Scholar]
  15. Reedy B. L. Usefulness of a gazetteer of general practice. Br Med J. 1975 Nov 15;4(5993):419–419. doi: 10.1136/bmj.4.5993.419. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Reyes F. I., Winter J. S., Faiman C. Pituitary-ovarian interrelationships during the puerperium. Am J Obstet Gynecol. 1972 Nov 1;114(5):589–594. doi: 10.1016/0002-9378(72)90833-2. [DOI] [PubMed] [Google Scholar]
  17. Rimoin D. L., Holzman G. B., Merimee T. J., Rabinowitz D., Barnes A. C., Tyson J. E., McKusick V. A. Lactation in the absence of human growth hormone. J Clin Endocrinol Metab. 1968 Aug;28(8):1183–1188. doi: 10.1210/jcem-28-8-1183. [DOI] [PubMed] [Google Scholar]
  18. Rolland R., Schellekens L. A new approach to the inhibition of puerperal lactation. J Obstet Gynaecol Br Commonw. 1973 Nov;80(11):945–951. doi: 10.1111/j.1471-0528.1973.tb02954.x. [DOI] [PubMed] [Google Scholar]
  19. Shiu R. P., Kelly P. A., Friesen H. G. Radioreceptor assay for prolactin and other lactogenic hormones. Science. 1973 Jun 1;180(4089):968–971. doi: 10.1126/science.180.4089.968. [DOI] [PubMed] [Google Scholar]
  20. Thorner M. O., Besser G. M., Hagen C., McNeilly A. S. Proceedings: The relationship between prolactin and gonadotrophins: effects of clomiphene administration in normal men. J Endocrinol. 1974 Nov;63(2):43P–44P. [PubMed] [Google Scholar]
  21. Tolis G., Somma M., Van Campenhout J., Friesen H. Prolactin secretion in sixty-five patients with galactorrhea. Am J Obstet Gynecol. 1974 Jan 1;118(1):91–101. doi: 10.1016/s0002-9378(16)33651-1. [DOI] [PubMed] [Google Scholar]
  22. Turkington R. W. Stimulation of RNA synthesis in isolated mammary cells by insulin and prolactin bound to sepharose. Biochem Biophys Res Commun. 1970 Dec 9;41(5):1362–1367. doi: 10.1016/0006-291x(70)90239-1. [DOI] [PubMed] [Google Scholar]
  23. Tyson J. E., Friesen H. G. Factors influencing the secretion of human prolactin and growth hormone in menstrual and gestational women. Am J Obstet Gynecol. 1973 Jun 1;116(3):377–387. doi: 10.1016/s0002-9378(15)31297-7. [DOI] [PubMed] [Google Scholar]
  24. Tyson J. E., Hwang P., Guyda H., Friesen H. G. Studies of prolactin secretion in human pregnancy. Am J Obstet Gynecol. 1972 May 1;113(1):14–20. doi: 10.1016/0002-9378(72)90446-2. [DOI] [PubMed] [Google Scholar]
  25. Zarate A., Canales E. S., Soria J., Ruiz F., MacGregor C. Ovarian refractoriness during lactation in women: effect of gonadotropin stimulation. Am J Obstet Gynecol. 1972 Apr 15;112(8):1130–1132. doi: 10.1016/0002-9378(72)90192-5. [DOI] [PubMed] [Google Scholar]

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