Effects of Adrenal Cortical Steroids on Calcium Metabolism

Radioactive calcium (Ca45) was used to investigate the effects of hydrocortisone and prednisolone on calcium metabolism in the rat. It was found that the absorption of Ca45 by the intestines was unimpaired by the administration of hydrocortisone. The administration of hydrocortisone or prednisolone to rats recently injected with Ca45 resulted in an increased urinary radiocalcium. This increase varied with the dosage, potency and persistence of the steroid in the body. The uptake of Ca45 by the femurs of both normal and nephrectomized rats was inhibited by the administration of hydrocortisone. Inanition resulted in a very slight inhibition of Ca45 uptake by bone. Hydrocortisone exerted no observable mobilization on total bone calcium.