| Abstract: | The influence of diluted Ringer solution on ovulation and maturation of common frog oocytes stimulated in vitro by homologous pituitary extract (0.005 pit/ml) or progesterone (1 pg/ml) was studied. During wintering, the dilution of Ringer solution led to a decreased percentage of oocytes ovulated and matured under the influence of both inducers. As the season of reproduction approached, the dependence of oocyte maturation and ovulation on the Ringer solution dilution weakened. Possible causes of different dependence of the ovulation of amphibian and sturgeon oocytes stimulated by gonadotropic hormones or progesterone on the culture medium osmolality is discussed. |
