Steroid hormone secretion by testicular tissue from African catfish,Clarias gariepinus,in primary culture: identification and quantification by gas chromatography — mass spectrometry |
| |
Authors: | G J Vermeulen J G D Lambert M J P Lenczowski H J Th Goos |
| |
Institution: | (1) Department of Experimental Zoology, Research Group of Comparative Endocrinology, University of Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands;(2) Department of Experimental Zoology, Research Group of Comparative Endocrinology, University of Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands |
| |
Abstract: | With the final aim of identifying the testicular steroids involved in the feedback mechanism of the hypothalamus-pituitary-gonad
axis, steroid secretion by the testis of African catfish, Clarias gariepinus, was studied in vitro, by means of gas chromatography followed by mass spectrometry. Testicular fragments of sexually mature catfish raised in
captivity were incubated in L-15 medium with and without catfish pituitary extract (cfPE). Without adding cfPE, 22 steroids
could be identified, amongst which 11β-hydroxyandrostenedione, 11β-hydroxytestosterone, 11-ketotestosterone and 11-ketoandrostenedione
were dominating. After incubation in the presence of cfPE, the concentrations of the four 11-oxygenated steroids were increased
about 4-fold. The amounts of pregnane derivatives in the incubation medium showed the largest increases in the presence of
cfPE. 5β-Pregnane-triol levels, for example, were 60-fold higher than in the medium from control incubations. The secretion
of 5α- and 5β-androstanes was also stimulated by cfPE.
The stimulation was not equal for all steroids, indicating that cfPE not only stimulates total steroidogenesis by increasing
the availability of cholesterol, but also by influencing specific steroid converting enzyme activities.
Part of this work was presented at the IVth International Symposium on the Reproductive Physiology of Fish, 7–12 July 1991, Norwich, U.K. |
| |
Keywords: | gas chromatography-mass spectrometry teleosts testis steroids |
本文献已被 SpringerLink 等数据库收录! |
|