[Comparative characteristics of the sex steroid content in the blood plasma of the big-mouthed buffalo, silver carp and channel catfish during reproduction].
A radioimmunoassay was to determine the content of estrogens, progestins and androgens in the blood plasma of female and male big-mouthed buffalo, silver carp and canal sheatfish before reproduction and in the first two species during reproduction as well. It was shown that sexual hormones of all 3 groups were present in the blood of males and females of the species under study, the androgen concentration being significantly higher than the estrogen and progestin content in species of both sexes. Sexual dimorphism in the estrogen and androgen content in the blood of the fishes before reproduction was revealed. An exception was a silver carp with the absence of sex differences in the androgen content. There were no significant differences in the initial progestin levels in the species of both sexes. Sex differences in the time-course of gonadal hormones during reproduction were revealed: an increase in the level of steroids of all 3 groups was observed during ovulation in females, that of androgens and progestins only in females of the studied species excluding silver carp. No increase in the concentration of androgens was observed in male silver carps during reproduction. In spite of the general regularities of the time-course of sexual steroids in the reproduction of the studied species of fish significant specific differences were noted in the absolute values of sexual hormone concentrations.
D000728:Androgens / Q000097:blood; D000818:Animals; D002347:Carps / Q000097:blood*; D003530:Cyprinidae / Q000097:blood*; D004967:Estrogens / Q000097:blood; D005260:Female; D005399:Fishes / Q000097:blood*; D012739:Gonadal Steroid Hormones / Q000097:blood*; D008297:Male; D010902:Pituitary Gland; D011372:Progestins / Q000097:blood; D012098:Reproduction; D012727:Sex Characteristics; D013045:Species Specificity; D014020:Tissue Extracts / Q000494:pharmacology
D000728:Androgens; D004967:Estrogens; D012739:Gonadal Steroid Hormones; D011372:Progestins; D014020:Tissue Extracts
Sravnitel'naia kharakteristika soderzhaniia polovykh steroidov v plazme krovi bol'sherotogo buffalo, belogo tolstolobika i kanal'nogo soma pri razmnozhenii.