NSILA-carrier protein abolishes the action of nonsuppressible insulin-like activity (NSILA-S) on perfused rat heart.
Human serum in a concentration of 10% in the perfusion medium failed to increase glucose uptake by the isolated perfused rat heart, indicating that nonsuppressible insulin-like activity (NSILA) in whole serum was inactive in this system. When NSILA-carrier protein was added to partially purified NSILA-S, its biological activity on the rat heart disappeared. In contrast, the action of insulin was not affected by the presence of NSILA-carrier protein. Binding of 125I-labelled NSILA-S to rat heart was inhibited by NSILA-carrier protein. 125I-labelled insulin binding was not inhibited. These results support the hypothesis that NSILA-S bound to serum carrier protein is a large molecular compound which does not readily diffuse out of the capillary bed and therefore does not exert insulin-like effects in vivo.
D000818:Animals; D001682:Biological Availability; D002352:Carrier Proteins / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010477:Perfusion; D011485:Protein Binding; D051381:Rats; D014907:Whales
D002352:Carrier Proteins; D007328:Insulin