Effect of Tetracycline on Retention of Calcium and Strontium in Rodents. ∗

Summary

Tetracycline (TC) administered repeatedly in doses totaling as much as 1200 mg/kg body weight, by either the intramuscular or intraperitoneal route, had no significant effect on the body retention of either Ca⁴⁷ or Sr⁸⁵ injected into mice or rats. Nor were the amounts of these radionuclides found in the bones reduced by such treatment. Oxytetracycline (OTC) was shown to have a greater chemical affinity for calcium ions than for strontium ions in vitro. Repeated large doses of OTC in the toxic range stunted the growth of young rats and caused pathological changes in bone tissue resembling those observed in hyperparathyroidism.

Although TC and OTC in large amounts can alter the normal metabolic interrelationships between calcium ions and bone tissue, they have no significant value as agents for reducing a potentially hazardous body or skeletal burden of radiostrontium.

We wish to acknowledge the valuable technical assistance of E. Flynn, M. Hepler, E. James, P. Suzuki, R. Hamel and G. Burdick.