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 rabbit's 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 Slyke's 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.