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Exp Clin Endocrinol Diabetes 1992; 99(1): 3-7
DOI: 10.1055/s-0029-1211122
Original

© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York

Indirect Effects of Progesterone on the Synthesis and Secretion of Prolactin in Mammotroph-Enriched Cells

N. Shimokawa1 , Y. Kato1 , 2 , M. Hattori1 , K. Wakabayashi
  • 1Hormone Assay Center (Director: Prof. Dr. K. Wakabayashi), Gunma University, Maebashi/Japan
  • 2Departments of Protein Chemistry (Director: Prof. Dr. K. Iwai), Institute of Endocrinology (Director: Prof. Dr. K. Kurosumi), Gunma University, Maebashi/Japan
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Publikationsverlauf

1991

Publikationsdatum:
15. Juli 2009 (online)

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Summary

To elucidate the role of steroid hormones in the synthesis and secretion of prolactin (PRL), a mammotrophenriched cell preparation was made by centrifugal elutriation of trypsin-dispersed anterior pituitary cells from adult male rats. The mammotrophs were enriched by about 2-fold in comparison with those in the initial cell suspension. On the other hand, the ratio of enrichment of gonadotrophs, thyrotrophs and somatotrophs was less than onetenth. The sepa rated mammotrophs were incubated in media containing 17 β-estradiol and/or progesterone. 17 β-estradiol increased the levels of PRL in the medium and the cells to 300% and 140%, respectively, and the content of messenger RNA (mRNA) to 193%, whereas progesterone had no such effects. Furthermore, progesterone had no influence on the 17 β-estradiol-induced increase in the levels of PRL and the contents of PRL mRNA. These results suggest that 17 β-estradiol regulates PRL synthesis and secretion in mammotrophs, whereas progesterone does not.

Key words

Rat PRL mRNA - Centrifugal elutriation - Mammotroph-enriched cells - Steroids treatment