Deb S, Jamaluddin M, Bhattacharya S, Bhadra R, Datta A G
Gen Comp Endocrinol. 1985 Mar;57(3):491-7. doi: 10.1016/0016-6480(85)90232-1.
Murrel (Channa punctatus Bloch) ovarian tissues were incubated in vitro with or without piscine gonadotrophins and then subjected to subcellular fractionation followed by nonesterified cholesterol (cholesterol) assay. Gonadotrophin from salmon (SG-G100), tilapia (TL1MS), and sturgeon (S27MS) depleted cholesterol in the mitochondrial fraction, whereas cholesterol remained unchanged in other subcellular fractions. Aminoglutethimide, an inhibitor of mitochondrial cholesterol side-chain cleavage, blocked the depletion of mitochondrial cholesterol in response to SG-G100 and murrel pituitary extract. When ovarian tissue containing [4-14C]cholesterol was challenged with SG-G100 in vitro, a dose-dependent decrease of mitochondrial [4-14C]cholesterol was observed. Increasing concentrations (1, 2, 4, 6, or 8 micrograms/incubation) of SG-G100, TL1MS, and S27MS resulted in a clear linear depletion of mitochondrial cholesterol. The slope of the dose-response curve in different individual fish was found to be distinctly uniform and parallel. The slopes of the standard curves obtained with TL1MS and S27MS were greater than that with SG-G100, indicating that tilapia and sturgeon gonadotrophins are more potent. Carp pituitary gonadotrophin content, determined by using these standard curves, showed the sensitivity and precision of this bioassay.
将墨瑞（斑鳢）的卵巢组织在有或没有鱼类促性腺激素的情况下进行体外培养，然后进行亚细胞分级分离，随后测定非酯化胆固醇（胆固醇）。来自鲑鱼（SG-G100）、罗非鱼（TL1MS）和鲟鱼（S27MS）的促性腺激素使线粒体部分的胆固醇减少，而其他亚细胞部分的胆固醇保持不变。氨基导眠能，一种线粒体胆固醇侧链裂解的抑制剂，可阻断因SG-G100和墨瑞垂体提取物导致的线粒体胆固醇减少。当含有[4-14C]胆固醇的卵巢组织在体外受到SG-G100刺激时，观察到线粒体[4-14C]胆固醇呈剂量依赖性减少。SG-G100、TL1MS和S27MS浓度增加（1、2、4、6或8微克/孵育）导致线粒体胆固醇明显呈线性减少。发现在不同个体鱼类中剂量反应曲线的斜率明显一致且平行。用TL1MS和S27MS获得的标准曲线斜率大于用SG-G100获得的，表明罗非鱼和鲟鱼的促性腺激素更有效。使用这些标准曲线测定鲤鱼垂体促性腺激素含量，显示了该生物测定的灵敏度和精密度。
