THE TOXICITY OF STRONTIUM AND CALCIUM

¹ From the Laboratories of Pharmacology and Physiology, Woman's Medical College of Pennsylvania, Philadelphia, Pa.

1. The relative toxicity of intravenously administered strontium and calcium depends on the species tested. In rats the toxicity of strontium exceeds slightly that of calcium in doses producing a mortality less than 60 per cent, but in larger doses there is no significant difference between these ions. In mice strontium is much less toxic than calcium.

2. An equimolecular mixture of strontium and calcium acetates in rats exhibits a toxicity equal to that of the most toxic ion regardless of the other ion, in the range up to a mortality of 85 per cent. In mice the mixture of the ions exerts a synergistic action producing a mortality slightly higher than that expected by calculating the total concentration of cations as that of the most toxic ion.

3. Strontium is partially antagonized by pentobarbital, but calcium is not.

4. Electrocardiographic studies showed that strontium produced death by respiratory failure in ninety per cent of the rats, and that calcium produced death by cardiac failure in exactly the same percentage.