Effect of Intravenous Injections of Alkali on Physiological Action of Curare.

Abstract

In an earlier paper 1 it was shown that a decrease in the pH of the blood, produced prior to the administration of lethal doses of strychnine, prevented violent tetanus and death. It was considered important to try the reciprocal experiment, that is, the effect of administering alkali to dogs that had previously received a lethal dose of curare.

Dogs used in this experiment received, intravenously, 5.7 mg. of curare per kilo of body weight. The drug used was the product of Burroughs, Wellcome & Co. Eight or 10 minutes after injection, when paralysis of the muscles, except the respiratory muscles, had appeared, a 5% solution of NaHCO₃ was injected intravenously. Complete recovery occurred within 15 minutes after approximately 3.0 gm. of NaHCO₃ had been introduced. The “curare effect” did not reappear.

At the onset of muscle paralysis the pH and CO₂ capacity begin to fall. The acidosis produced evidently augments the effect of curare but is not, in itself, sufficiently pronounced to produce coma. Introduction of NaHCO₃ not only corrects anoxemia but also possibly neutralizes the curare effect at the myo-neural junction.

All controls died of respiratory paralysis within 20 minutes after receiving curare.

The following table gives the data from one of our experimental animals: