Effect of cortisone on magnesium metabolism in the rabbit

¹ Department of Medicine, University of Colorado School of Medicine, Denver, Colorado

External balance studies for magnesium and serial isotopic determinations of the exchangeable magnesium content were made in seven adult male rabbits before and during a 14-day series of daily injections of cortisone acetate (10 mg/kg of body weight). A significant reduction in serum magnesium concentration was found at 8 and 14 days. The exchangeable magnesium content was increased at 8 days. In another group of animals relative tissue activity studies showed that the uptake of Mg²⁸ by the heart, appendix and muscle was increased on the 8th day of cortisone administration. The results suggest that this dose of cortisone does not alter the external balance of magnesium, but that a more subtle internal change in the dynamics and distribution of magnesium does occur.