The relation of the sugar content and concentration of the blood to urine formation. (Preliminary report.)

Abstract

The present experiments were performed in an effort to establish a standard of comparison for further experiments involving the study of the fate of sugar injected into the circulatory system under various conditions.

Various amounts of a dextrose solution (40 gm. in 40 c.c. water) were injected into the femoral veins of dogs under local anesthesia, and 20 c.c. of blood drawn from the femoral artery at 15-minute intervals. Twenty c.c. of citrated dog's blood previously prepared were injected into the artery immediately afterward, thus maintaining the normal concentration of the blood as indicated by the specific gravity and hemoglobin percentage. The specific gravity, hemoglobin and sugar content of the blood were determined, and also the urine obtained by catheter was measured and its sugar content estimated. Specific gravity was determined with a 10 c.c. pycnometer; hemoglobin with the Sahli instrument; blood sugar and urine sugar by the Lewis-Benedict and Benedict methods, respectively.

I. Fisher and Wishart have presented evidence that (con-trary to Starling's hypothesis) after the ingestion of 50 gm. of dex-trose by a dog, there is a diminished formation of urine in spite of a dilution of the blood, as indicated by hemoglobin determinations.

Similar results were obtained also in the present series of experiments after intravenous injections, estimations of the specific gravity as well as the hemoglobin content of the blood being made. The following experiments indicate clearly that simple increase or decrease in the concentration of the blood following injection of crystalloids does not necessarily result in a corresponding increase or decrease in urine formation, and that there may be a definite diuresis without any material change in the concentration of the blood.

II. Complete results of the experiments would be too bulky for publication, but the following summary will show the relation of blood sugar, blood concentration and diuresis.