Effect of Acidosis in Strychnine Poisoning.

Abstract

It has been demonstrated by a number of investigators that changes in the reaction of the blood toward the acid side prevent the clonic contraction and spasticity of the skeletal muscles in parathyroid tetany. The experiments reported here show that a decrease in the pH of the blood produced prior to the administration of lethal doses of strychnine, prevents violent tetanus, convulsions and death. Acidosis was produced in 7 dogs by subcutaneous injections of nephro-toxic substances such as uranium nitrate and sodium tartrate. When the pH of the blood dropped to about 7.2 and the CO2 capacity to around 22 volumes %, the dogs received subcutaneously 1/160 gr. per kilo of strychnine sulphate. Ten minutes later slight muscle tremors and spasms developed. In all cases recovery occurred within 45 minutes. One dog died 1 hour following injection of the lethal dose of strychnine. In this case death was apparently due to uranium nitrate poisoning. In other series of dogs acidosis was produced by means other than those involving impairment of renal function. This was brought about by administering NH4Cl to one series of animals and CO2 to another. Muscle spasms from which the dogs soon recovered, followed the injections of a lethal dose of strychnine. From the results we obtained it is evident that it is the initial drop in pH occurring before injection of the strychnine and not the fall produced by convulsions and the resulting anoxemia that is effective in preventing convulsions and death from strychnine poisoning. The data from 1 of our experimental and 1 of our control dogs are presented in Table I.