Relief of Parathyroid Tetany by Injections of Uranium Nitrate.

Abstract

Recent studies from this laboratory^1,2 have shown that slight changes in the acid-base equilibrium, with a shift in the reaction of the blood toward the acid side, exert a profound effect upon the tetany of parathyroid insufficiency.

The writer and his collaborators have shown that asphyxiation by CO₂ of dogs presenting violent tetany promptly brings about a return to normal in so far as tetany symptoms are concerned. The disappearance of symptoms was correlated with disturbance of the acid-base equilibrium, i. e., lowered CO₂ capacity, CO₂ content and pH, due to rise in lactic acid. Tetany again supervened following a return to a normal acid-base balance and disappearance of the lactic acid. The total serum calcium remained unchanged by the CO₂ treatment, despite the fact the animals seemed normal and were free from tetany.

Since the effect of the CO₂ lasts but a brief period, and since it was considered desirable to study the experimental animals over longer periods, the present experiment with uranium nitrate was undertaken. This substance has been extensively employed in the study of renal function since it induces marked pathological changes in the kidneys when injected, and it is a well established fact that a profound acid intoxication develops in animals so treated. It is not definitely known to what acid or acids the acidosis of uranium nitrate poisoning is due. The intoxication develops slowly and reaches a maximum between the 4th and 8th day following injection.

In the present experiments both old and young dogs were used. They were thyroparathyroidectomizecl and allowed to develop marked tetany symptoms. They were then bled for CO,₂ capacity, pH and serum calcium. It has been the experience of those working in this laboratory 3 that the CO,₂ capacity, and pH of tetany dogs are normal.