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Steroidogenesis in pre- and postspawned ovaries of feral African catfish, Clarias gariepinus

1987; Elsevier BV; Volume: 63; Issue: 1-4 Linguagem: Inglês

10.1016/0044-8486(87)90066-4

1873-5622

W.G.E.J. Schoonen, A.M. Van Bennekum, J.G.D. Lambert, Willem Viveen, P. G. W. J. van Oordt,

Aquaculture Nutrition and Growth

Steroidogenesis in pre- and postspawned ovaries of Clarias gariepinus, collected in the Hula Nature Reserve in Israel, was studied following in vitro incubation with [3H] -pregnenolone or [3H] -androstenedione as precursors. In both experimental groups the ovaries synthesized progesterone, 17α-hydroxyprogesterone, 17α, 20β-dihydroxy-4-pregnen-3-one, androstenedione, testosterone, estrone, estradiol-17β, and several 5β-reduced C21- and C19-steroids. Testosterone and most of the 5β-reduced C21- and C19-steroids were also identified in a conjugated form as steroid glucuronides. In postspawned ovaries the production of these steroid glucuronides, especially testosterone-glucuronide and 5β-androstane-3α,17β-diol-glucuronide, and the steroid 5β-pregnane-3α,17α,20β-triol had increased significantly in comparison with prespawned ovaries. In these prespawned ovaries, on the other hand, androgen production, mainly testosterone, prevailed. It is suggested that the water-soluble compounds formed in relatively high amounts in postspawned ovaries are excreted into the external environment, where they may function as sex pheromones during the spawning period.