Follicular fluid stimulation of 3 beta-hydroxysteroid dehydrogenase activity in vitro.
Follicular fluid from porcine antral follicles stimulates progesterone secretion by porcine granulosa cells from small antral follicles in vitro. Fluid from large (6-12 mm) follicles has more stimulatory activity than fluid from smaller follicles. In this study, we have examined the action of charcoal-treated and filtered follicular fluid on 3 beta-hydroxysteroid dehydrogenase activity (3 beta-HSD) and the ability of exogenous pregnenolone to increase progesterone secretion. Granulosa cells cultured with 30% follicular fluid in TC 199 (v/v) for 3 days were less dependent on the presence of exogenous pregnenolone to enhance their progesterone secretion and exhibited more 3 beta-HSD activity than control cells incubated in 30% serum in TC 199. The apparent Vmax of 3 beta-HSD was increased 80% in follicular fluid-treated cells over that observed in controls (4.8 vs. 2.6 nM/min/100 mg protein) whereas the apparent Kms for 3 beta-HSD were similar (1.3 +/- 0.34 microM) in both experimental and control cells.
D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000818:Animals; D001826:Body Fluids / Q000502:physiology; D002478:Cells, Cultured; D004247:DNA / Q000032:analysis; D005260:Female; D006107:Granulosa Cells / Q000201:enzymology; D006080:Ovarian Follicle / Q000502:physiology*; D011284:Pregnenolone / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D011863:Radioimmunoassay; D013385:Succinate Dehydrogenase / Q000378:metabolism; D013552:Swine
D011374:Progesterone; D011284:Pregnenolone; D004247:DNA; D015096:3-Hydroxysteroid Dehydrogenases; D013385:Succinate Dehydrogenase