Effect of Viosterol on Serum Calcium of Parathyroidectomized Rats.

Abstract

Recently Hess 1 suggested that the effect of viosterol in raising the serum calcium level was through the parathyroids. This suggestion was based on his observations that in monkeys and dogs fed large doses of viosterol the serum calcium level frequently rose to 13-16 mg. %. After thyroparathyroidectomy, however, large doses of viosterol failed to raise the calcium above the tetanic level. Greenwald 2 reports similar observations with cod liver oil and irradiated ergosterol. On the other hand, Jones, 3 Brougher, 4 Urechia and Popovicius 5 report that antirachitic agents, when given in large doses, are able to raise the serum calcium level and ameliorate the tetanic symptoms in thyroparathyroidectomized animals. The diets in these experiments are either not mentioned or are of an inconstant composition. Greenwald's diets were usually of the high phosphorus and low calcium type, and he attributes the beneficial results of vitamin D in one of his animals to an accidental mixture of calcium in the infusorial earth and that in Brougher's experiments to the administration of milk.

In the preceding paper 6 the importance of the calcium and phosphorus of the diet in relation to the serum calcium level after parathyroidectomy was stressed. In the present communication the effect of viosterol and of diet on parathyroid tetany is reported.

The results may be summarized as follows: 1. Low calcium and optimal∗ phosphorus diet. (a) When viosterol is added to this diet in dosages of 5% equivalent to cod liver oil† moderate elevation of the serum calcium may be observed after 20 days, and the animals continued on this diet with mild or no tetany for several months. The serum calcium levels ranged between 6.9 to 8.1 mg.%.