The Glucagon Content of Crystalline Insulin Preparations

Open Access
Publisher Website
Google Scholar
Abstract
Hyper-glycemic response in cats is used as the basis of a sensitive and reproducible assay for glucagon. Starved animals were anesthetized, and the femoral vein was exposed in both legs. A quantity of glucagon was given that would cause a blood sugar rise of 20 to 50 mg % within 10-15 minutes. After 25 minutes a standard preparation of known potency was given and the blood sugar rise was again determined. The quotient, obtained by dividing the net maximum increase produced by the unknown by that caused by the standard preparation, was used as a measure of activity. Interference by the hypoglycemic action of insulin in test samples was prevented by incubating the samples with insulin. A number of samples of Zn-insulin were found to contain 0.3-0.5% of the hyperglycemic factor.