Harold L. Hansen

The Variation of Anesthetic Efficiency of Procaine Hydrochloride and Procaine Borate With pH

Experimental evidence obtained both in the laboratory 1 and in the clinic 2 shows that the borate of diethylamino ethyl p-amino-benzoate, procaine borate, has a higher anesthetic efficiency than the hydrochloride of the same base. The fact that the solutions of procaine borate used had a pH of about 8.4 while the procaine hydrochloride solutions had a pH of approximately 5.6 suggested that it might be worth while to determine the effect of variation of pH on the anesthetic efficiency of the two drugs. O. Gros 3 found that addition of excess sodium bicarbonate or secondary sodium phosphate markedly increases the anesthetic efficiency of procaine hydrochloride. Sollmann 4 corroborated and extended these findings. Regnier, 5 from his results on alkalinization of cocaine hydrochloride solutions, also concluded that increase in alkalinity augments anesthetic properties. The present work consisted in a comparison of the anesthetic efficiency of procaine borate and procaine hydrochloride solution at varying hydrogen ion concentrations by the method of Adams 6 on goldfish with modifications suggested by Dailey 7 and Benedict. The solutions used were brought to the desired pH with N/10 sodium hydroxide and N/10 hydrochloric acid. The pH determinations were made with a Leeds-Northrup Quinhydrone potentiometer. All solutions used were of the same concentration with respect to the anesthetic base, the procaine hydrochloride solutions containing 1 gm. of the hydrochloride in 500 cc. of solution and the procaine borate solutions containing 1.638 gm. of the borate in 500 cc. of solution. The results obtained are given in the graph. Each point represents the average time required to anesthetize 3 or more fish, anesthesia being determined by lack of response to stimulation of fins or tail.

Blood Chloride Changes in Relation to Diuresis in Dogs.

There is considerable practical as well as theoretical importance to a complete explanation of the mode of action of the various types of diuretics. In various recent contributions to this field, Curtis has studied the problem in rabbits and upholds the view that the specific diuretics have their primary action on the tissues, mobilizing electrolytes, principally chlorides, which in turn act as stimulants to the kidney and increase the formation of urine. Various workers have pointed out certain apparent differences of behavior between the rabbits kidney on the one hand and that of dog and man on the other. It seemed advisable, therefore, to determine the effect of certain diuretics on the blood chloride levels in relation to the diuretic response in dogs. Female dogs were prepared for urine collection by transplanting the trigone of the bladder to the anterior abdominal wall. This procedure obviates the effects of catheterization and enables accurate observations on urine flow to be made. Blood was drawn from either the saphenous or external jugular vein and the chlorides determined by the micro method of Van Slyke. These determinations were checked in many instances by Van Slykes macro method. Diuresis was produced with euphyllin (theophylline ethylene diamine), salyrgan, and novasurol. No consistent significant variations in the blood chloride level were noted either preceding, during, or following the diuresis. Such negative results might be due to the activity of the kidney so that any tendency to a rise in the blood chloride level might be offset by increased excretion. To test this possibility several dogs were nephrectomized. Twenty-four hours later, these same diuretics were administered and the blood chloride level followed. No significant changes were observed. Another method of testing the ability of these diuretics to mobilize chlorides from the tissues to the blood stream was tried.