Interleukin-1 alpha increases thecal progesterone production of preovulatory follicles in cyclic hamsters.
Adult cyclic hamsters were used to study the effects of interleukin-1 alpha (IL-1 alpha) on in vitro steroidogenesis in preovulatory follicles. IL-1 alpha increased progesterone secretion by preovulatory follicles during a 24-h incubation in RPMI-1640 medium containing hCG (100 mIU/ml) (progesterone levels: 17.5 +/- 2.2 vs. 10.6 +/- 1.9 ng/follicle/ml, p less than 0.05). IL-1 alpha alone had no effect on follicular steroidogenesis. The source of increased progesterone secretion was the thecae (9.8 +/- 1.0 vs. 5.8 +/- 0.4 ng/2 thecae/ml, p less than 0.01) and not the granulosa cells (6.6 +/- 0.2 vs. 6.8 +/- 0.5 ng/20,000 viable granulosa cells/ml). IL-1 alpha also stimulated production of testosterone in thecae of preovulatory follicles. The follicular progesterone increase was dependent on the time of incubation and dose of IL-1 alpha. IL-1 alpha at 5-50 U/ml maximally stimulated progesterone production in the preovulatory follicles, and no significant effect of IL-1 alpha was observed until the 12th hour of incubation. The effects of IL-1 alpha on in vitro steroidogenesis in preantral follicles, experimentally induced atretic preovulatory follicles, and newly formed corpora lutea were examined. IL-1 alpha in the presence of hCG also significantly increased progesterone secretion by atretic preovulatory follicles. In the incubation of preantral follicles or newly formed corpora lutea, however, IL-1 alpha did not alter steroidogenesis. These results indicate that IL-1 alpha stimulates progesterone secretion by preovulatory follicles and that the target tissue for this effect is the thecal layer.(ABSTRACT TRUNCATED AT 250 WORDS)
Nakamura
Y
Y
Department of Obstetrics and Gynecology, Yamaguchi University School of Medicine, Japan.
Kato
H
H
Terranova
P F
PF
D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D003338:Corpus Luteum / Q000378:metabolism; D006224:Cricetinae; D004958:Estradiol / Q000096:biosynthesis; D005260:Female; D007375:Interleukin-1 / Q000494:pharmacology*; D008647:Mesocricetus; D006080:Ovarian Follicle / Q000378:metabolism*; D010060:Ovulation / Q000502:physiology*; D011374:Progesterone / Q000096:biosynthesis* / Q000378:metabolism; D013739:Testosterone / Q000096:biosynthesis; D013799:Theca Cells / Q000187:drug effects / Q000378:metabolism*
D006063:Chorionic Gonadotropin; D007375:Interleukin-1; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol