The production of lactic acid in diabetes following the administion of insulin.

Abstract

It is evident from recent work on normal animals that following the administration of insulin in large doses marked changes occur in the glucose, lactic acid, 1 and inorganic phosphate 2 content of the blood. Since these constituents seem to be intimately concerned with the metabolism of carbohydrate, it was desirable to extend the study of them to human beings, more especially to diabetics. Also, since the combustion of glucose as well as the formation of lactic acid has a profound influence on the respiratory quotient the metabolism was determined using the respiration calorimeter of the Russell Sage Institute of Pathology.

Four patients with uncomplicated diabetes were studied. They varied from extremely mild to moderately severe. In each case the effect of a single intravenous dose varying from 8 to 33 units of insulin (Iletin, Lilly) was observed. The blood was taken before, and between 1 and 2 hours after, the injection, and analyzed for sugar, lactic acid, and inorganic phosphates. The respiratory metabolism was determined in the calorimeter beginning about 15 to 75 minutes after the injection and continuing for 45 minutes. The patient was then removed from the calorimeter, and a blood sample was drawn for analysis. Immediately after, he was returned to the calorimeter and observed for another three hours. For comparison, a three-hour basal observation of the previous day was used.

The results in the table clearly demonstrate that the invariable fall of blood glucose following insulin administration is not always accompanied by a rise in lactic acid.

Three separate observations were made on patient E. V. In only one instance was the lactic acid concentration increased after insulin. Although the absolute drop in blood sugar was greater in the other two, 214 mg., and 82 mg. per 100 cc. respectively, no rise in the lactic acid was found.