[Effect of colchicine on the in vitro maturation of frog oocytes as affected by a suspension of hypophysis and progesterone].

The influence of colchicine (250 micrograms/ml) on in vitro oocyte maturation in the frog Rana temporaria was studied. The maturation of oocytes was induced by treatment of the follicles with pituitary suspension or progesterone. The gonadotropin-dependent period upon oocyte maturation in all studied females was shortened under the effect of colchicine. The dose of progesterone required for 50% GVBD in the colchicine-treated follicles of 4 out of 11 females was lower than in the intact follicles, in the other cases the dose was the same. Colchicine did not influence the time of 50% GVBD.