Effects of gonadotrophins on the cumulus oophorus of isolated rat Graafian follicles.
Graafian follicles were extirpated before the endogenous LH surge on the day prior to ovulation from PMS-injected immature rats. They were incubated in chemically defined medium in presence or absence of gonadotrophins for 4-10 h. After incubation the oocyte-cumulus complexes were recovered from the follicles and one group inspected by Nomarski interference contrast microscopy and one group was placed in saline containing hyaluronidase. In hormone-free medium both the oocyte and the cumulus cells remained morphologically unchanged: a dictyate oocyte surrounded by a compact mass of cumulus cells. Hyaluronidase did not detach cells from the cumulus structure. However, in presence of LH or FSH morphological changes developed in both cell types: the oocyte resumed meiosis as revealed by germinal vesicle breakdown and polar body formation; the cumulus structure became dispersed and embedded in a viscous matrix. The individual cumulus cells displayed pseudopodia-like processes of the cell surface. Treatment with hyaluronidase resulted in detachment of cells from the cumulus. The effects of LH described on the oocyte and cumulus cells were unimpaired in presence of cyanoketone or aminoglutethimide although these agents blocked the follicular relase of progesterone, estradiol and androstenedione as revealed by RIA. The results indicate that a close functional relationship exists between the two cell types of the cumulus oophorus, the oocyte and the cumulus granulosa cells. Both cell types are affected directly or indirectly by gonadotrophins and characteristical morphological changes develop synchronously in both cell types.
D000616:Aminoglutethimide / Q000494:pharmacology; D000735:Androstenedione / Q000494:pharmacology; D000818:Animals; D003489:Cyanoketone / Q000494:pharmacology; D004347:Drug Interactions; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006107:Granulosa Cells / Q000187:drug effects; D006821:Hyaluronoglucosaminidase / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000494:pharmacology*; D009865:Oocytes / Q000187:drug effects*; D006080:Ovarian Follicle / Q000187:drug effects*; D010063:Ovum / Q000187:drug effects*; D011374:Progesterone / Q000494:pharmacology; D011388:Prolactin / Q000494:pharmacology*; D051381:Rats
D000616:Aminoglutethimide; D000735:Androstenedione; D003489:Cyanoketone; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D006821:Hyaluronoglucosaminidase