Inhibitory action of porcine follicular fluid upon granulosa cell luteinization in vitro: assay and influence of follicular maturation.
Culture medium 199 supplemented with follicular fluid from 1-2 mm antral porcine follicles inhibited spontaneous luteinization of granulosa cells from preovulatory porcine follicles in vitro. Three characteristics of luteinization were inhibited: morphological transformation, progesterone secretion, and accumulation of cyclic AMP in response to LH. The last was inhibited more effectively by culture media containing 50% follicular fluid than by media containing 20% follicular fluid. The inhibitory actions of the follicular fluid were not altered by charcoal or petroleum ether extraction. Follicular fluid from large follicles (6-12 mm) did not exhibit any of these inhibitory actions. These observations may indicate the presence of a luteinization inhibitor in the fluid of small follicles which (1) is lost by the time the follicle reaches the preovulatory stage, or (2) is overcome by a stimulatory agent which may accumulate as the follicle grows.
D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D003864:Depression, Chemical; D005260:Female; D006107:Granulosa Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D007986:Luteinizing Hormone / Q000494:pharmacology; D006080:Ovarian Follicle / Q000502:physiology*; D011374:Progesterone / Q000378:metabolism; D013552:Swine
D011374:Progesterone; D007986:Luteinizing Hormone; D000242:Cyclic AMP