[Effects of low calcium on myocardial necrosis of Keshan disease by food preference].

It was noticed that monotonous diet which imitated the composition of diet for the susceptible population of Keshan disease with a habit of food preference was prominently low in calcium and selenium. The plasma calcium ion content of rats kept on a monotonous diet was significantly lowered to merely half the content of the stock diet group with significant lowering of GSH-px activity. After peritoneal injection of furosemide, the plasma calcium ion contents of the monotonous diet group were further lowered significantly and signs of calcium deficiency, such as muscle tremor, spasm and convulsion might occur. If anoxic factor NaNO2 acted simultaneously, acute and severe myocardial necrosis developed. Morphologically, the myocardial necrosis was similar to that in Keshan disease. When monotonous diet was supplemented with only calcium, the growth state of the rats was significantly improved, and the degree of myocardial necrosis was significantly decreased. Supplement of calcium, selenium as well as vitamin E, seemed more effective. It is suggested that low selenium is the basic factor of endemic pathogenesis of Keshan disease, and low calcium intake by food preference among the susceptible population of Keshan disease plays an important role in the pathogenesis of myocardial necrosis in Keshan disease.