Long-Period-Effect of Moderate Mg Deficiency on Circulation Parameters in Rats Treated with Cadmium

抄録

The present study was carried out to elucidate the effect of a moderately Mg-deficient diet on circulation parameters such as blood pressure and cardiac functions in rats treated with Cd. Forty male Wistar rats were divided into the following groups to evaluate the effect of two different dietary Mg concentrations in regard to Cd treatment: normal dietary Mg and no Cd treatment (group N); normal Mg plus Cd treatment (group N + Cd); moderately Mg-deficient diet defined as 40% concentration of normal level and no Cd treatment (group D); and moderate Mg-deficient diet plus Cd treatment (group D + Cd). Subcutaneous injection of Cd in the backs of the animals at 1 mg/kg body weight was performed twice a day for 7 consecutive days and the animals then were maintained with two different diets and without Cd treatment for an additional period of 203 days before analysis. Comparison of the two groups of N + Cd and D + Cd showed that ingestion of the Mg-deficient diet markedly increased cardiac output and decreased total peripheral resistance without altering blood pressure. The Ca concentration in the heart of D + Cd rats was not increased compared with that from N rats, although there was significant interaction between Mg deficiency and Cd treatment on the Ca concentration in the heart, suggesting that moderate Mg deficiency did not cause myocardial necrosis or impair cardiac contraction in the rats treated with Cd.