Effects of follicle regulatory protein on thecal aromatase and 3 beta-hydroxysteroid dehydrogenase activity in medium- and large-sized pig follicles.
Theca was excised from large (greater than 8 mm) and medium-sized (3-6 mm) pig follicles and prepared as monolayer cultures in serum-free media. After 24 h cells were treated with (1) M199 (control), (2) 5 i.u. hCG, (3) 100 micrograms or 100 ng FRP or (4) hCG (5 i.u.) + FRP (100 micrograms or 100 ng). At 3, 6, 12, 24 and 48 h after treatment, progesterone, oestradiol, androstenedione and testosterone were measured in media. Formation of progesterone by microsomal fractions incubated (37 degrees C) with 1 microM-pregnenolone + 5-microM-NAD+ for 1 h was used as a measure of 3 beta-HSD activity. Aromatase activity was determined by incubating cells with [3H]testosterone for 3 h (37 degrees C) and measuring 3H2O release. In theca from large follicles, hCG enhanced 3 beta-HSD activity after 48 h (P less than 0.05) and secretion of progesterone after 36 h. FRP alone inhibited 3 beta-HSD activity at 36 and 72 h, but had little effect on progesterone secretion. FRP inhibited (P less than 0.05) the hCG-induced increase in 3 beta-HSD activity at 36, 48 and 72 h. HCG enhanced aromatase activity after 48 h while FRP prevented (P less than 0.05) the hCG-induced increase in aromatase activity at 48 and 72 h. Secretion of oestradiol was enhanced (P less than 0.05) at 48 h but inhibited at 72 h by hCG. FRP alone had little effect on secretion of oestradiol but hCG + FRP was inhibitory at 72 h.(ABSTRACT TRUNCATED AT 250 WORDS)
Tonetta
S A
SA
Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles 90033.
DeVinna
R S
RS
diZerega
G S
GS
D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000818:Animals; D001141:Aromatase / Q000378:metabolism*; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D005260:Female; D036341:Intercellular Signaling Peptides and Proteins; D006080:Ovarian Follicle / Q000502:physiology; D010455:Peptides / Q000494:pharmacology*; D013552:Swine; D013799:Theca Cells / Q000187:drug effects / Q000201:enzymology*
D006063:Chorionic Gonadotropin; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; C018355:intraovarian peptides; D015096:3-Hydroxysteroid Dehydrogenases; D001141:Aromatase