Phosphorus Changes in Totally ParathyroidectomizedRana Pipiens

Abstract

Previous studies reported from our laboratories have shown that there is a decrease in plasma calcium in parathyroidectomized Rana pipiens, followed by a gradual increase approximately to control levels. Urine calcium was significantly higher in the operated animals than in the controls. In the experiments reported herein, plasma phosphorus was found to increase within 2 hours after parathyroid ablation, followed by a gradual decrease. However, even after 14 days the plasma phosphorus still was significantly higher than in unoperated animals. Urine phosphorus also was significantly above that of the control animals within 2 hours. Therefore, the increase in plasma phosphorus could not have been due to an increased reabsorption of phosphorus by the mesonephros. Eventually the high urinary phosphorus declined gradually, but in a fluctuating course. Plasma and urine calcium determinations were made at 2, 4, 6, 12 and 24 hours after parathyroidectomy. Plasma calcium concentrations did not change within the first 24 hours, whereas increases in urine calcium appeared as early as 2 hours after gland removal. The rapid increase in plasma phosphorus and the slow decrease in plasma calcium indicate that changes in calcium values in plasma are independent of changes in the plasma phosphorus concentrations.