[Steroids in the reproductive function regulation in fish]

Following ovulation cortisol and testosterone concentrations were lower in the stellate sturgeon coelomic fluid than in the blood serum, whereas the levels of progesterone was lower in the blood. Specific cytosol binding of sex steroids in the brain and the gonads differed in fish before and after the maturation. In the forebrain, the specific binding of androgens dropped sharply after the ovulation. In the hypothalamus the specific binding of estrogens was the highest after the final maturation and ovulation. A certain correlation between the blood sex steroids concentrations and their specific binding in the brain and gonads cytosol, were established.