Study on Calcium Metabolism in Rats treated with Lead

To know the calcium metabolism of rats treated with lead acetate, the serum and urinary calcium levels were determined, and the hepatic calcium content was measured. No differences were demonstrated in the serum and urinary calcium levels in the lead-administered and control rats but significant difference was found between the two groups in the serum and urinary amount of inorganic phosphorus and in the serum alkaline phosphatase activity. Correlation between alkaline phosphatase activity and inorganic phosphorus was demonstrated in the serum. In the thyroparathyroidectomized rats, the serum calcium level of the lead-treated group increased 1.25 times (P<0.01) that of the untreated group. The calcium content in liver of rats treated with lead was about 22 times that of the control rats. In the case of thyroparathyroidectomized rats, the former was only about 3 times that of the latter. From these facts it is demonstrated that thyroid and parathyroid glands in lead-poisoned rat play an important part in high calcium accumulation in the liver.