[Study of oxidative damage on mitochondrial membrane of myocardium deficient in selenium]

Keshan disease (KD) is an endemic cardiomyopathy with membrane damage of the myocardial mitochondria. This paper reports the results of feeding guinea pigs with a forage obtained from KD endemic area. The selenium (Se) content and glutathione peroxidase activity in blood, tissues, mitochondria, microsome and supernatant of myocardium and liver cells of the experimental group were decreased. Additionally, the activity of glutathione-S-transferase was also decreased to some extent, instead of being increased in normal cases, and the content of lipid peroxide and hydroperoxide was increased. At the same time, cardiolipin in mitochondria, and the activity of cytochrome C oxidase (CCO, an enzyme binding with mitochondrial membrane) were also reduced accompanied with oxidative damage and disorder of function of the membrane. Anyhow, when exogenous cardiolipin was added in the purified endemic CCO solution, it was capable of restoring CCO activity significantly. The significance of Se deficiency and unbalanced diet in pathogenesis of Keshan disease is discussed.