Open AccessSynthesis of the Allylic Regulatory Steroid, 3α-Hydroxy-4-Pregnen-20-One, by Rat Granulosa Cells and its Regulation by Gonadotropins1
Author(s) -
John P. Wiebe,
Gillian C. de Gannes,
M. Dallaire
Publication year - 1994
Publication title -
biology of reproduction
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.366
H-Index - 180
eISSN - 1529-7268
pISSN - 0006-3363
DOI - 10.1095/biolreprod50.4.956
Subject(s) - medicine , endocrinology , theca , estrous cycle , ovary , alpha (finance) , biology , granulosa cell , ovarian follicle , follicle , theca interna , gonadotropin , steroid , hormone , construct validity , nursing , patient satisfaction
The production of the allylic regulatory steroid 3 alpha-hydroxy-4-pregnen-20-one (3 alpha HP) in the rat ovary was examined and compared to progesterone levels through use of specific RIAs that had been validated by capillary gas chromatography-mass spectrometry (GC/MS). Results showed that serum levels of 3 alpha HP are comparable to levels of progesterone at all ages examined. In the 4-day cycling rat, serum levels of 3 alpha HP were highest during diestrus and lowest during proestrus and estrus, while serum FSH levels were highest during proestrus/estrus and lowest during diestrus. Hypophysectomy resulted in decreases in ovarian and serum 3 alpha HP. Treatment of hypophysectomized rats with eCG, but not hCG, increased ovarian and serum 3 alpha HP, while serum progesterone was elevated by treatment with hCG. Ovariectomy resulted in a 55-60% reduction in serum 3 alpha HP, indicating that ovaries are a substantial, but not exclusive, source of 3 alpha HP in serum. As further evidence, cultures of preparations consisting primarily of either granulosa cells or granulosa/theca "shells" produced 3 alpha HP in time-dependent amounts comparable to those of progesterone. Granulosa cells in culture showed a significant increase in accumulation of 3 alpha HP (and progesterone) due to treatment with FSH, but not LH. In contrast to the granulosa-only cell cultures, follicle shells consisting of theca and granulosa cells responded to either LH or FSH treatment with marked increases in 3 alpha HP; increases resulting from combined treatment (FSH + LH) were significantly greater than those due to each hormone alone, but the increases were not additives.(ABSTRACT TRUNCATED AT 250 WORDS)