The prevention and correction of hypocalcemia in the parathyroidectomized rat by portacaval shunt.

Adult rats underwent end-to-side portacaval shunt either 30 days prior to or 12 days following parathyroidectomy. When portacaval shunt was performed initially, the serum calcium failed to decrease following subsequent parathyroidectomy and remained within normal levels up to 110 days. When parathyroidectomy first was done, the significant hypocalcemia was corrected subsequently by portacaval shunt and serum calcium remained close to the normal level up to 75 days. The effect of portacaval shunt depended on the calcium content of the food and was obtained only when rats were fed by a regular diet. Rats on a calcium-deficient diet were hypocalcemic, similar to the parathyroidectomized rats without the portacaval shunt. Prolonged calcium-deficient diet alone, without parathyroidectomy, did not by itself result in hypocalcemia either in the intact rat or in the portacaval shunted rat. The data indicate that portacaval shunt prevents and corrects hypocalcemia in the parathyroidectomized Lewis rat as long as sufficient calcium is available in the diet.