Author(s): Zhao Weixin R. S. Wright
Pages: 532-538
Year: 1988 Issue:  6
Journal: Oceanologia et Limnologia Sinica
Keyword:  类固醇激素; 大西洋鲑; 离体培育; 分泌性; 大麻哈鱼; 雄烯二酮; 培养液; 促性腺激素; 性类固醇激素; 羟孕酮;
Abstract: The levels of serum progesterone, 17α-hydroxyprogesterone, androstenedione, testosterone 11-oxotestosterone (11-OT) and 17α-hydroxy-20β-dihydroprogesterone (17α20βP) in mature male (with milt) Atlantic salmon (Salmo salar) were measured with radioimmunoassay. 11-OT level (23.2±7.12 ng/ml) was much higher than testosterone (4.7±1.42 ng/ml ) in October. 17α20βP was also found in the circulating blood with the level of 7.6±2.45 ng/ml in October. But it was less than 0.1 ng/ml in September.Testes from a mature Atlantic salmon (with milt) were cut into small pieces. One gram such testicular fragments were incubated in 3 ml trout balanced saline solution buffered with HEPES-NaOH containing 0.1 or 1 ng/ml chum salmon (Oncorhynchus keta) gonadotrophin (GTH). Incubation media were taken at intervals during six days incubation and measured. GTH stimulated an obvious release of 11-OT and the level was considerably high. Both testosterone and androstenedione levels rose slowly. Both progesterone and 17α-hydroxyproges-terone levels were extremely low in the medium. 17α20βP level rose quickly after two days incubation. The levels of steroids in the medium did not show GTH dose-dependent. From those results, it shows that 11-OT is a more important and active steroid, which responses to GTH. 17α20βP may be involved in spermiation. Progesterone, 17α-hydroxyprogesterone, androstenedione and testosterone may be the precursors of 17α20βP and 11-OT.