Zhang Surong, Zhou Zongcan, Fu Juanling
Department of Toxicology, School of Public Health, Peking University Health Science Center, Beijing 100083, China.
Environ Res. 2003 Oct;93(2):149-57. doi: 10.1016/s0013-9351(03)00109-9.
Manganese (Mn) is an essential trace element found in many enzymes. As is the case for many essential trace elements, excessive Mn is toxic. Individuals suffering from manganese toxicity exhibit several symptoms, which are similar to those frequently observed in cases of Parkinson's disease. In this investigation, we studied the effect of manganese chloride (7.5, 15.0, and 30.0 mg/kg body weight) on mitochondrial function and attempted to ascertain the mechanism of manganese-induced mitochondrial dysfunction. The production of reactive oxygen species in mitochondria of rat liver and brain was assayed using 2',7'-dichlorofluorescin diacetate, and the activities of respiratory chain enzymes were examined spectrophotometrically. Monoamine oxidase (MAO) activity was assayed by measuring reduction of benzylamine. Manganese and calcium content in mitochondria were determined by atomic absorption spectrophotometry. These results indicate that manganese chloride (MnCl2) can decrease MAO activity and inhibit the respiratory chain. Manganese can accumulate in mitochondria and inhibit efflux of calcium. There is a significant inverse correlation between the amount of superoxide radicals and the specific activities of the mitochondria enzymes. Mitochondrial function was significantly affected in both males and females.
锰（Mn）是一种存在于多种酶中的必需微量元素。与许多必需微量元素一样，过量的锰具有毒性。患有锰中毒的个体表现出多种症状，这些症状与帕金森病患者中经常观察到的症状相似。在本研究中，我们研究了氯化锰（7.5、15.0和30.0毫克/千克体重）对线粒体功能的影响，并试图确定锰诱导线粒体功能障碍的机制。使用2',7'-二氯荧光素二乙酸酯测定大鼠肝脏和脑组织线粒体中活性氧的产生，并通过分光光度法检测呼吸链酶的活性。通过测量苄胺的还原量来测定单胺氧化酶（MAO）的活性。通过原子吸收分光光度法测定线粒体中的锰和钙含量。这些结果表明，氯化锰（MnCl2）可降低MAO活性并抑制呼吸链。锰可在线粒体中蓄积并抑制钙的外流。超氧自由基的量与线粒体酶的比活性之间存在显著的负相关。雄性和雌性的线粒体功能均受到显著影响。
