The phosphate and calcium content of serum in the condition of guanidine tetany

Abstract

In the altered metabolism in parathyroidectomized dogs, Greenwald 4 found a marked decrease in the elimination of phosphate in the urine together with a distinct retention in the blood.

It has been established that the lack of parathyroid is accompanied by increased elimination of ammonia, decreased acid excretion and the lowering of the hydrogen ion concentration. The same conditions are manifested after the administration of guanidine hydrochloride. 1 The increase in guanidine nitrogen was found by Koch 2 and Burns and Sharpe 3 in experimental parathyroid tetany and also in idiopathic tetany. In a recent communication 4 we reported that the above-mentioned phenomena were an accompaniment of the acidosis produced by guanidine administration and also suggested that phosphates might be retained in the body to neutralize the acids formed by the muscular activity.

Another fact that in parathyroid tetany, the calcium content of the tissues was decreased was reported by Sabbatani 5 and Quest 6 and by many other investigators. In this country MacCallum and Voegtlin 7 confirmed the above statements and also reported a marked reduction in the blood calcium caused by the increased output in the urine and feces. It, therefore, seemed advisable to inquire into the phosphate and calcium changes in the blood in guanidine tetany and to compare these changes with those occurring in parathyroid tetany in order to decide whether the increase in guanidine nitrogen is the only cause of this phenomenon or whether other factors are involved in the production of parathyroid tetany.

Marriott and Howland's methods were employed in this investigation. Rabbits were used and two samples of blood were drawn from the jugular vein; one before the subcutaneous administration of a sublethal dose of guanidine hydrochloride and the other after-about 10 to 48 hours after the injection of the drug. It is necessary to wait for the second sample of blood until the acidosis is well developed, though most animals do not live long after this condition becomes severe.