Department of Zoology, Utkal University, Bhubaneswar 751 004, India.
Comp Biochem Physiol C Toxicol Pharmacol. 2012 Mar;155(2):228-37. doi: 10.1016/j.cbpc.2011.08.009. Epub 2011 Sep 10.
Mitochondrial respiration, activities of electron transport chain enzymes and formation of oxidative stress parameters were investigated in mitochondria isolated from gill tissue of mud crabs (Scylla serrata) as a function of salinity (10 ppt, 17 ppt and 35 ppt). Mitochondrial oxygen consumption rate was higher for succinate as substrate compared with those of glutamate, malate and pyruvate. Complex I and complex II mediated respirations were higher at low salinity (10 ppt) than high salinity (17 ppt and 35 ppt). Although activities of electron transport chain enzymes particularly complexes I (EC 1.6.5.3), II (EC 1.3.99.1) and II-III (EC 1.3.2.1) were elevated linearly in response to salinity treatment, activity of complex V (ATPase, EC 3.6.1.34) was decreased at 35 ppt salinity. However, ATPase activity was higher at 17 ppt salinity in comparison to 10 ppt and 17 ppt salinity. Results of the experiment suggest that high salinity (35 ppt) causes hypoxic state in mitochondria of mud crabs. Hypoxic condition induced by high salinity was accompanied with increased hydrogen peroxide production resulting oxidative stress in mitochondria of crabs. A possible mechanism of hypoxia-induced reactive oxygen species generation and OS due to salinity stress in the crabs is discussed.
研究了盐度（10 ppt、17 ppt 和 35 ppt）对泥蟹（Scylla serrata）鳃组织分离的线粒体中呼吸作用、电子传递链酶的活性和氧化应激参数的形成的影响。与谷氨酸、苹果酸和丙酮酸相比，作为底物的琥珀酸盐的线粒体耗氧率更高。在低盐度（10 ppt）下，复合物 I 和 II 介导的呼吸作用高于高盐度（17 ppt 和 35 ppt）。尽管电子传递链酶的活性，特别是复合物 I（EC 1.6.5.3）、II（EC 1.3.99.1）和 II-III（EC 1.3.2.1），随着盐度处理呈线性增加，但在 35 ppt 盐度下，复合物 V（ATP 酶，EC 3.6.1.34）的活性降低。然而，与 10 ppt 和 17 ppt 盐度相比，17 ppt 盐度下的 ATP 酶活性更高。实验结果表明，高盐度（35 ppt）导致泥蟹线粒体处于缺氧状态。高盐度引起的缺氧状态伴随着过氧化氢产生的增加，导致蟹类线粒体的氧化应激。讨论了盐度应激引起的缺氧诱导活性氧生成和 OS 的可能机制。
