[Insulin and 17-oxycorticosteroids in unfertilized eggs and in embryos of the loach]

Loach eggs are stated to possess some quantities of insulin or insulin-like substances with a positive reaction to antiinsulin antiserum. The level of these components is five times as high 30 minutes after fertilization, and does not change for the next 20 hours of the embryo development. No 17-oxycorticosteroids were detected in loach eggs and embryos during first four hours of the development; they appeared only at the blastula stage and at the state of gastrula their level increases considerably. It is supposed that insulin or insulin-like substances participate in metabolism regulation and cell differentiation of fish embryos during early stages of embryogenesis.