PRECONDITIONING WITH ISCHEMIA OR ADENOSINE PROTECTS SKELETAL-MUSCLE FROM ISCHEMIC TISSUE REPERFUSION INJURY

Prolonged tissue ischemia and subsequent reperfusion results in signif icant tissue injury due to the ischemic-reperfusion (IR) syndrome. Isc hemic preconditioning (IPC) or adenosine (ADO) pretreatment are known to protect IR injury in cardiac muscle. Our aim was to determine wheth er IPC or ADO pretreatment attenuates and protects against ischemic ti ssue reperfusion injury in skeletal muscle. Rats were anesthetized and global hindlimb ischemia was induced by 60 min of suprarenal aortic c lamping followed by 30 min of reperfusion period. The degree of skelet al muscle dysfunction was determined by decreases in maximum contracti le force, and adenosine triphosphate (ATP) and creatine phosphate (CP) levels of extensor digitorum longus (EDL) muscle. The distal tendon o f the EDL was attached to a force transducer for maximum isometric for ce measurement. Samples were taken from the EDL for measurement of ATP and CP levels. The following were protective protocols prior to the I R challenge: (1) four consecutive 5-min periods of ischemia separated by B-min reperfusion periods (PC/I) or (2) i.v. adenosine infusion (35 0 mu g/kg/min x 10 min, PC/A). Our data suggest that pretreatment with brief periods of ischemia or systemic ADO infusion attenuates ischemi c tissue reperfusion injury in skeletal muscle. [GRAPHICS] P < 0.05 v s control, *P < 0.05 vs IR. (C) 1996 Academic Press, Inc.