NON-SUPPRESSIBLE INSULIN-LIKE ACTIVITY DURING ACUTE METABOLIC AND ENDOCRINE CHANGES IN DOGS

Abstract

Non-suppressible insulin-like activity (NSILA-S) was determined in dogs after acute changes in the blood sugar and after injection of growth hormone (GH]. Serum was chromatographed over Sephadex G-50 columns equilibrated in 1 M acetic acid and NSILA-S was determined in the fractions between 55 and 85% column volume using a protein binding assay and the conventional fat pad assay. The results obtained with these 2 methods correlated rather well (r = 0.74). Hyperglycemia induced by an i.v. glucose load, by i.v. administration of mannoheptulose or both was not followed by an increase in NSILA-S levels. The injection of insulin and human GH did not lead to alterations of the NSILA-S levels. Total NSILA-S levels in the dog do not change acutely following manipulations of the blood sugar and NSILA-S probably plays no role in the regulation of blood glucose.