Laboratorio Ecotoxicología, Comisión de Investigaciones Científicas (CIC), Facultad Cs. Ex. y Nat.-UNMDP, Funes 3350, 7600 Mar del Plata, Argentina.
Instituto de Investigaciones Marinas y Costeras (IIMyC)- UNMDP, CONICET, Facultad Cs. Ex. y Nat. Lab. Ecotoxicología, Funes 3350, 7600 Mar del Plata, Argentina.
Ecotoxicol Environ Saf. 2018 Aug 30;158:44-49. doi: 10.1016/j.ecoenv.2018.03.096. Epub 2018 Apr 12.
Endosulfan (ES) modifies the ultrastructure of skeletal muscle fibers and causes changes to the swimming behavior of fish. The objectives of the present work were to evaluate, in fishes of Australoheros facetus, 1) the integrity of myofibrils (Mf) by the analysis of SDS-PAGE profiles, and 2) the functionality of Mf through the microscopically monitoring of the contraction and changes in Mg Ca- ATPase and Mg(EGTA) -ATPase activities. As expected, after the addition of the contraction buffer, control fish Mf contracted. On the contrary, Mf from fish exposed at 0.5 μg/L ES showed a partial contraction and none of the fish exposed at 10 μg/L ES contracted. As judged by its high Mg Ca ATPase activity and low Mg (EGTA) ATPase activity, control Mf showed good functionality. In Mf from fish exposed to 0.5 and 10 μg/L ES the activities of these enzymes were similar, suggesting denaturation or degradation of some component of tropomyosin-troponin complex. SDS-PAGE patterns of Mf from fish exposed to ES showed degradation of the myosin heavy chain and of tropomyosin. Similar values of lipid peroxidation (TBARS) were found in both control and exposed Mf, suggesting that lipid oxidation was not be related to the above-mentioned changes. The observed effects expand the knowledge of ES action in muscles and could be used as biomarkers of damage in fishes exposed to organochlorine compounds like the insecticide endosulfan.
硫丹（ES）会改变骨骼肌纤维的超微结构，并改变鱼类的游动行为。本研究的目的是评估，在Australoheros facetus 鱼类中，1） 通过 SDS-PAGE 图谱分析评估肌原纤维（Mf）的完整性，以及 2） 通过微观监测收缩以及 Mg Ca-ATP 酶和 Mg（EGTA）-ATP 酶活性的变化来评估 Mf 的功能。如预期的那样，在加入收缩缓冲液后，对照组鱼的 Mf 收缩。相反，暴露于 0.5μg/L ES 的鱼的 Mf 显示部分收缩，而暴露于 10μg/L ES 的鱼的 Mf 均未收缩。根据其高 Mg Ca ATP 酶活性和低 Mg（EGTA）ATP 酶活性判断，对照组 Mf 显示出良好的功能。暴露于 0.5 和 10μg/L ES 的鱼的 Mf 中的这些酶的活性相似，表明肌球蛋白重链和原肌球蛋白-肌钙蛋白复合物的一些成分发生变性或降解。暴露于 ES 的鱼的 Mf 的 SDS-PAGE 图谱显示肌球蛋白重链和原肌球蛋白降解。在对照组和暴露组的 Mf 中均发现相似的脂质过氧化（TBARS）值，这表明脂质氧化与上述变化无关。观察到的这些效应扩展了 ES 对肌肉作用的认识，并可用作暴露于有机氯化合物（如杀虫剂硫丹）的鱼类的损伤生物标志物。
