Effect of FSH, LH, LH-RH and arginine-vasotocin on the production of steroids, nonapeptide hormones and cGMP by rabbits granulosa cells isolated at different stages of reproductive cycle.

Granulosa cells isolated from ovaries of non-cycling, cycling and pregnant rabbits of the same age were cultured in vitro either without or with pFSH (1 micrograms/ml), bLH (1 IU/ml), LH-RH (25 ng/ml) or arginine-8-vasotocin (100 ng/ml). The production of immunoreactive progesterone, estradiol-17 beta, oxytocin, arginine-8-vasopressin and cGMP was analyzed. The gonadotropins did not show any significant effects on the cells isolated from non-cycling and cycling rabbits, but not from these of pregnant ones. LH-RH inhibited and vasotocin stimulated progesterone production. All hormones used stimulated estradiol release from cells of non-cycling rabbits, while in a case of cycling animals no change was found. In the cell from pregnant females the release of estradiol was enhanced after LH treatment only. The treatment with FSH and LH (but not with LH-RH or vasotocin) resulted in a remarkable rise of granulosa vasopressin surge irrespectively to the reproductive stage. Oxytocin production by granulosa cells incubated either without or with LH, LH-RH or vasotocin was undetectable. However, FSH strongly stimulated oxytocin release. FSH and in lesser extent, LH or LH-RH (but not vasotocin) activated granulosa cGMP production in the cells from cycling and pregnant (but not from non-cycling) animals. It was also found that, in contrast to other reproductive stages, basal progesterone release from the cells of pregnant rabbits was increased, while in a case of non-cycling animals the basal estradiol release was decreased and that of cGMP was increased.(ABSTRACT TRUNCATED AT 250 WORDS)