Levels of 17 alpha,20 alpha-dihydroxy-4-pregnen-3-one, 3 beta,17 alpha,20 alpha-trihydroxy-5 beta-pregnane, and other sex steroids, in blood plasma of male dab, Limanda limanda (marine flatfish) injected with human chorionic gonadotrophin.
In a previous study, plasma sex steroid levels were measured in female dab (Limanda limanda) induced to ovulate by injections of human chorionic gonadotrophin (HCG). In the present study, a similar experiment was carried out on male dabs. In common with female dabs, 17 alpha,20 alpha-dihydroxy-4-pregnen-3-one and 3 beta,17 alpha,20 alpha-trihydroxy-5 beta-pregnane showed the greatest response. Their plasma levels increased, respectively, from 6 +/- 1.6 and 13 +/- 6.2 ng/ml to ca. 62 ng/ml within 36 hr and then decreased. Levels of both steroids remained low in fish injected with saline. There was no statistically significant effect of HCG on plasma testosterone or 11-ketotestosterone concentrations. Initial levels of both hormones were between 10 and 20 ng/ml, and decreased simultaneously in both HCG- and saline-injected fish. Levels of 17 alpha-hydroxy-4-pregnen-3,20-dione, 17 alpha,20 beta-dihydroxy-4-pregnen-3-one, 11-deoxycortisol, and 17 alpha,20 beta, 21-trihydroxy-4-pregnen-3-one were mostly below the detection limits of the assays (0.4 ng/ml). There was no statistically significant effect of HCG on either the total volume of milt collected or the proportion occupied by spermatozoa.
Universidade do Algarve, Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Faro, Portugal.
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Canario
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Scott
D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D005412:Flatfishes / Q000097:blood*; D006908:Hydroxyprogesterones / Q000097:blood*; D007700:Kinetics; D008297:Male; D011279:Pregnanetriol / Q000031:analogs & derivatives* / Q000097:blood; D012016:Reference Values; D013737:Testis / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D006063:Chorionic Gonadotropin; D006908:Hydroxyprogesterones; C007433:17,20-dihydroxy-4-pregnen-3-one; D011279:Pregnanetriol; C062103:3,17,20-trihydroxypregnane