A Reducing Substance in the Urine of Cats Under Nembutal Anesthesia

Abstract

A series of 15 cats were given intraperitoneal injections of nembutal (sodium iso-amytal, penta-barbital), the average dose being 60 mg. per kilo. Urine samples were collected at intervals after the injection and later analyzed for reducing substances by Sumner's method. In certain instances the results thus obtained were checked by the use of Benedict's quantitative reagent. Simultaneously blood samples were taken and later analyzed for “blood sugar” by the Randle-Grigg modification of the Folin-Wu Micro Method. These observations were made in the course of experiments to determine the effect of stimulation of the tuber cinereum upon carbohydrate metabolism. Rather extensive surgical procedures under deep nembutal anesthesia were required in the experiments. The bladder was exposed and emptied and the urethra cannulated from one to 2 hours after the injection of nembutal. The first sample of urine was taken about an hour after the urethra was cannulated and from 2 to 3 hours after the administration of nembutal. This sample always showed the presence of an abnormal quantity of reducing substance, usually the maximum obtained during the experiment, the concentration decreasing progressively in subsequent samples. This maximum reduction where the lowest maximum was obtained, was equivalent to that produced by 240 mg. % of glucose. In the experiment where the largest maximum was found, the reducing substance was equivalent to that produced by 1575 mg. % of glucose. An average maximum value, equivalent to that produced by 1045 mg. % of glucose, was obtained. The amount of reducing substance in the urine was definitely related to the time interval following the injection of nembutal and not to the “blood sugar” concentration. Often in the later stages of the experiment the reducing substance would be decreasing in amount while the blood sugar was increasing.