Insulin-like Activity of Bradykinin on Amino Acid Balances Across the Human Forearm

Abstract

To investigate whether bradykinin which improves carbohydrate metabolism of skeletal muscle also exhibits insulin-like activity on amino acid metabolism, balances of O2 and 13 amino acids across the forearm and forearm blood flow were determined in normal subjects during the arterial infusion of insulin (n = 9; 250 .mu.U kg-1 per min), bradykinin (n = 7; 0.2 ng kg-1 per min) and papaverine (n = 5; 2 .mu.g kg-1 per min). As expected, the infusion of insulin exhibited significant reduction of the release of Gly, Pro, Val, Phe, Leu, Thr and Ile. Like insulin, bradykinin lessened the release of 9 amino acids: Gly, Ser, ornithine, Val, Leu, Ile and Tyr. Papaverine, which exhibited almost identical acceleration of forearm blood flow as bradykinin, did not influence the amino acid release from forearm muscle. Kinins liberated during muscle work might be involved in the work-induced insulin-like action on carbohydrate and on amino acid metabolism.