Exogenous progesterone reduces follicular prostaglandin E and 6-keto prostaglandin F-1 alpha in the cyclic hamster.
In cyclic hamsters, exogenous progesterone (100 micrograms) administered s.c. at 09:00 h on the day of dioestrus II reduced prostaglandin (PG) E and 6-keto PGF-1 alpha but not PGF concentrations in preovulatory follicles measured at 09:00 h of pro-oestrus. The injection of 10 micrograms ovine LH (NIADDK-oLH-25) concurrently with 100 micrograms progesterone on dioestrus II prevented the decline in follicular PGE and 6-keto PGF-1 alpha values. Administration of LH alone did not significantly alter follicular PG concentrations. Inhibition of follicular PGE accumulation by progesterone was due to a decline in granulosa PGE concentration and not thecal PGE. Progesterone administration also reduced follicular oestradiol concentrations. Administration of oestradiol-17-cyclopentanepropionate (ECP) (10 micrograms) with progesterone did not prevent the decline in follicular PGE and 6-keto PGF-1 alpha but did increase follicular PGF concentrations. However, ECP given alone on dioestrus II reduced follicular PGE and increased PGF concentrations in preovulatory follicles on pro-oestrus. It is concluded that exogenous progesterone administered on dioestrus II inhibits granulosa PGE and 6-keto PGF-1 alpha accumulation in preovulatory follicles, probably by reducing serum LH concentrations, and that the granulosa cells, which are LH-dependent, are a major source of follicular PGE.
Brannian
J D
JD
Department of Physiology, Ralph L. Smith Research Center, University of Kansas Medical Center, Kansas City 66103.
Terranova
P F
PF
D015121:6-Ketoprostaglandin F1 alpha / Q000378:metabolism*; D000735:Androstenedione / Q000378:metabolism; D000818:Animals; D006224:Cricetinae; D004031:Diestrus; D004958:Estradiol / Q000378:metabolism; D005260:Female; D006107:Granulosa Cells / Q000378:metabolism; D007986:Luteinizing Hormone / Q000494:pharmacology; D006080:Ovarian Follicle / Q000187:drug effects / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism / Q000494:pharmacology*; D011458:Prostaglandins E / Q000378:metabolism*; D011863:Radioimmunoassay / Q000379:methods
D011458:Prostaglandins E; D000735:Androstenedione; D011374:Progesterone; D004958:Estradiol; D015121:6-Ketoprostaglandin F1 alpha; D007986:Luteinizing Hormone