Inhibin-like activity in media from cultured rat granulosa cells collected throughout the oestrous cycle.
Granulosa cells of antral ovarian follicles from adult 5-day cyclic rats were cultured on each day of the cycle. The rat granulosa cell conditioned medium (rGCCM) was harvested and renewed on each day of a 4-day culture period. Inhibin-like activity and progesterone were estimated in rGCCM using an in-vitro bioassay system with dispersed rat anterior pituitary cells and radioimmunoassay respectively. Removal of steroids from rGCCM with dextran-coated charcoal was effective and did not significantly change the inhibin-like activity of the treated samples. On day 1 of culture the inhibin-like activity of rGCCM for each day of the oestrous cycle was 20-90% higher than on days 2, 3 and 4 of culture when low and constant levels were observed. Media collected after culture on days 1 and 2 from pro-oestrous cells contained larger amounts of inhibin-like activity than media collected on the other days of the cycle. On day 1 of culture, rGCCM from pro-oestrous cells contained higher concentrations of progesterone than that from cells collected on the other days of the cycle. On days 2, 3 and 4 progesterone levels in rGCCM were undetectable (less than 320 pmol/l) except in media from pro-oestrous cultures on day 2. Addition of FSH (62 micrograms/l) to granulosa cell cultures in medium with or without 10% fetal calf serum (FCS) did not alter the inhibin-like activity of rGCCM from pro-oestrous cells. The presence of FCS maintained the production of inhibin-like activity since rGCCM from cells cultured without FCS was devoid of FSH-suppressing activity after 3 days of culture.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D001681:Biological Assay; D002478:Cells, Cultured; D006224:Cricetinae; D003470:Culture Media; D004967:Estrogens / Q000378:metabolism; D004971:Estrus; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D007265:Inhibins / Q000378:metabolism*; D011247:Pregnancy; D011374:Progesterone / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D003470:Culture Media; D004967:Estrogens; D011374:Progesterone; D007265:Inhibins; D005640:Follicle Stimulating Hormone