Skip to main content
NCBI home page
Biochemical Journal logoLink to Biochemical Journal
. 1979 Sep 15;182(3):735–743. doi: 10.1042/bj1820735

Biosynthesis and degradation of prolactin in the rat anterior pituitary gland. Time course of incorporation of label in vitro and evidence for rapid degradation.

R Shenai, M Wallis
PMCID: PMC1161407  PMID: 518561

Abstract

Biosynthesis of prolactin was studied in anterior pituitary glands from female rats, incubated in vitro. In this system [3H]leucine was incorporated into pituitary proteins, including somatotropin (growth hormone) and prolactin. The rate of uptake of label into prolactin (and to a lesser extent into total protein) slowed considerably during the first 2 h of incubation, although the rate of uptake into somatotropin was constant for 8 h. The most probable explanation for this apparent decrease in the rate of prolactin synthesis is degradation of prolactin in the gland. Degradation of this hormone was also demonstrated by incubating prelabelled pituitaries in unlabelled medium and following the content of labelled prolactin, and by studying the hormonal content of pituitary glands (by radioimmunoassay) before and after incubation. Degradation of prolactin appears to be much more rapid than that of somatotropin, and may represent a physiological mechanism whereby over-accumulation of prolactin is prevented when secretion of the hormone has been rapidly switched off.

Full text

PDF
735

Selected References

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

  1. Asawaroengchai H., Nicoll C. S. Relationships among bioassay, radioimmunoassay and disc electrophoretic assay methods of measuring rat prolactin in pituitary tissue and incubation medium. J Endocrinol. 1977 May;73(2):301–308. doi: 10.1677/joe.0.0730301. [DOI] [PubMed] [Google Scholar]
  2. Augustine E. C., Macleod R. M. Prolactin and growth hormone synthesis: effects of perphenazine, alpha-methyltyrosine and estrogen in different thyroid states. Proc Soc Exp Biol Med. 1975 Dec;150(3):551–556. doi: 10.3181/00379727-150-39076. [DOI] [PubMed] [Google Scholar]
  3. Betteridge A., Wallis M. Biosynthesis of growth hormone in the rat anterior pituitary gland. Stimulation of biosynthesis in vitro by insulin. Biochem J. 1973 Aug;134(4):1103–1113. doi: 10.1042/bj1341103. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. DAVIS B. J. DISC ELECTROPHORESIS. II. METHOD AND APPLICATION TO HUMAN SERUM PROTEINS. Ann N Y Acad Sci. 1964 Dec 28;121:404–427. doi: 10.1111/j.1749-6632.1964.tb14213.x. [DOI] [PubMed] [Google Scholar]
  5. Desbuquois B., Aurbach G. D. Use of polyethylene glycol to separate free and antibody-bound peptide hormones in radioimmunoassays. J Clin Endocrinol Metab. 1971 Nov;33(5):732–738. doi: 10.1210/jcem-33-5-732. [DOI] [PubMed] [Google Scholar]
  6. Farquhar M. G., Reid J. J., Daniell L. W. Intracellular transport and packaging of prolactin: a quantitative electron microscope autoradiographic study of mammotrophs dissociated from rat pituitaries. Endocrinology. 1978 Jan;102(1):296–311. doi: 10.1210/endo-102-1-296. [DOI] [PubMed] [Google Scholar]
  7. Gay V. L., Midgley A. R., Jr, Niswender G. D. Patterns of gonadotrophin secretion associated with ovulation. Fed Proc. 1970 Nov-Dec;29(6):1880–1887. [PubMed] [Google Scholar]
  8. Hill M. K., Macleod R. M., Orcutt P. Dibutyryl cyclic AMP, adenosine and guanosine blockade of the dopamine, ergocryptine and apomorphine inhibition of prolactin release in vitro. Endocrinology. 1976 Dec;99(6):1612–1617. doi: 10.1210/endo-99-6-1612. [DOI] [PubMed] [Google Scholar]
  9. JONES A. E., FISHER J. N., LEWIS U. J., VANDERLAAN W. P. ELECTROPHORETIC COMPARISON OF PITUITARY GLANDS FROM MALE AND FEMALE RATS. Endocrinology. 1965 Apr;76:578–583. doi: 10.1210/endo-76-4-578. [DOI] [PubMed] [Google Scholar]
  10. Labrie F., Pelletier G., Lemay A., Borgeat P., Barden N., Dupont A., Savary M., Côté J., Boucher R. Control of protein synthesis in anterior pituitary gland. Acta Endocrinol Suppl (Copenh) 1973;180:301–340. doi: 10.1530/acta.0.074s301. [DOI] [PubMed] [Google Scholar]
  11. MORGAN J. F., MORTON H. J., PARKER R. C. Nutrition of animal cells in tissue culture; initial studies on a synthetic medium. Proc Soc Exp Biol Med. 1950 Jan;73(1):1–8. doi: 10.3181/00379727-73-17557. [DOI] [PubMed] [Google Scholar]
  12. MacLeod R. M., Abad A. On the control of prolactin and growth hormone synthesis in rat pituitary glands. Endocrinology. 1968 Oct;83(4):799–806. doi: 10.1210/endo-83-4-799. [DOI] [PubMed] [Google Scholar]
  13. Neill J. D. Effect of "stress" on serum prolactin and luteinizing hormone levels during the estrous cycle of the rat. Endocrinology. 1970 Dec;87(6):1192–1197. doi: 10.1210/endo-87-6-1192. [DOI] [PubMed] [Google Scholar]
  14. Pelletier G., Lemay A., Beraud G., Labrie F. Ultrastructural changes accompanying the stimulatory effect of N6-monobutyryl adenosine 3',5'-monophosphate on the release of growth hormone(GH), prolactin (PRL) and adrenocorticotropic hormone (ACTH) in rat anterior pituitary gland in vitro. Endocrinology. 1972 Nov;91(5):1355–1371. doi: 10.1210/endo-91-5-1355. [DOI] [PubMed] [Google Scholar]
  15. Shenai R., Wallis M. Proceedings: Control of prolactin biosynthesis in vitro by insulin. Biochem Soc Trans. 1974;2(5):955–956. doi: 10.1042/bst0020955. [DOI] [PubMed] [Google Scholar]
  16. Wallis M., Davies R. V., Daniels M. Preparation of internally labelled rat pituitary somatotropin (growth hormone). Biochem J. 1978 Mar 1;169(3):669–676. doi: 10.1042/bj1690669. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Zanini A., Giannattasio G. Polyacrylamide gel electrophoresis of rat anterior pituitary gland after different extraction procedures. J Endocrinol. 1972 Apr;53(1):177–178. doi: 10.1677/joe.0.0530177. [DOI] [PubMed] [Google Scholar]

Articles from Biochemical Journal are provided here courtesy of The Biochemical Society

RESOURCES