ISCHEMIC-REPERFUSED RAT SKELETAL-MUSCLE - THE EFFECT OF VASOACTIVE-INTESTINAL-PEPTIDE (VIP) ON CONTRACTILE-FORCE, OXYGENATION AND ANTIOXIDANT ENZYME-SYSTEMS

The effect of vasoactive intestinal peptide (VIP) on the nerve-stimula ted contraction, tissue oxygenation, lipid peroxidation and antioxidan t enzymes activities-superoxide dismutase and catalase was investigate d in the rat gastrocnemius muscle exposed to 4 h ischemia-4hr reperfus ion. Ischemia caused significant decrease in muscle contractile force, oxygenation and superoxide dismutase enzyme activity. Reperfusion of ischemic muscle increased the muscle contractile force and restored th e tissue oxygenation to the baseline lever. Superoxide dismutase and c atalase activities of reperfused muscle increased significantly. Howev er neither ischemia nor reperfusion affected gastrocnemius muscle malo ndialdehide (MDA) levels. VIP administration at the onset of reperfusi on significantly increased skeletal muscle contractile force and tissu e oxygenation even higher than baseline and reperfusion values. VIP al so normalized the increased superoxide dismutase and catalase activiti es of reperfused skeletal muscle. In conclusion, VIP, acting as a powe rful antioxidant and preserving contractile machinery seems to be a pr omising endogenous peptide that can salvage the skeletal muscle from s evere ischemia-reperfusion injury. (C) 1997 Elsevier Science Inc.