Beneficial effects of a calcium antagonist, nifedipine, on death and cardiovascular calcinosis induced by dietary magnesium deficiency in adult mice.

The effects of nifedipine on the survival rate and the cardiovascular calcinosis were investigated in dietary magnesium (Mg)-deficient mice. Male mice aged 8 to 10 weeks were fed with a diet which was either normal (0.07%) or deficient (0.007%) in Mg for 30 d. Nifedipine was added to the Mg-deficient diet for 30 d in a concentration of 1000 ppm. About 65% of Mg-deficient mice died within 30 d. In contrast, all the nifedipine-treated mice survived for 30 d. Mg-deficient mice showed hypomagnesaemia and hypocalcaemia which were not influenced by nifedipine treatment. Aortic and cardiac calcium contents increased in Mg-deficient mice, and these increments were normalized by nifedipine treatment. These results suggest that the life-saving effect of nifedipine in Mg-deficient mice might relate, at least in part, to the prevention of a deleterious increase in Ca in cardiovascular tissues.