Rabbit ovarian production of interleukin-6 and its potential effects on gonadotropin-induced progesterone secretion in granulosa and theca cells.
Recent studies suggest that non-steroid factors, such as cytokines, may play a role in ovarian processes. The purpose of this study was to explore cellular sites of interleukin (IL)-6 biosynthesis in rabbit follicles and to investigate IL-6 modulation in granulosa and theca cell functions. In this report development of rabbit preovulatory follicles was induced by 200 mIU equine chorionic gonadotropin (eCG) daily for 2 days. Seventy-two hours after the last injection ovaries were excised and granulosa and theca cells isolated. The two types of cells were preincubated for 24 h in Minimum Essential Medium (MEM) with 5% fetal calf serum (FCS), and then incubated for 24 h in MEM-2.5% FCS with appropriate stimulants. Results showed that rabbit granulosa and theca cell culture supernatants contained IL-6 bioactivity and that its production was inhibited by FSH and human CG and stimulated by IL-1. IL-6 inhibited gonadotropin-induced progesterone production, but not basal secretion, in both cell types, without a cytotoxic effect. IL-6 affected cAMP generation and steps distal to cAMP formation, but the mechanism of IL-6 action on progesterone differed in granulosa and theca cells. Taken together our results suggest that gonadotropins, by inhibiting IL-6 production, could control, in our model, IL-6 modulation of gonadotropin action on steroidogenesis.
Bréard
E
E
Laboratoire de Biochimie, EP 9 CNRS, IBBA Université de Caen, CHU Côte de Nacre, 14032 Caen Cedex, France.
Benhaïm
A
A
Féral
C
C
Leymarie
P
P
D000704:Analysis of Variance; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006065:Gonadotropins, Pituitary / Q000494:pharmacology*; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis*; D010053:Ovary / Q000187:drug effects / Q000378:metabolism*; D011374:Progesterone / Q000032:analysis / Q000096:biosynthesis*; D011817:Rabbits; D013799:Theca Cells / Q000187:drug effects / Q000378:metabolism
D006063:Chorionic Gonadotropin; D006065:Gonadotropins, Pituitary; D007375:Interleukin-1; D015850:Interleukin-6; D005576:Colforsin; D011374:Progesterone; D003994:Bucladesine; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP