PENTOXIFYLLINE ATTENUATES REPERFUSION INJURY IN SKELETAL-MUSCLE AFTERPARTIAL ISCHEMIA

Leukocytes have been shown to contribute to ischemia-reperfusion injur y in skeletal muscle. Pentoxifylline (PTXF), a xanthine-derived phosph odiesterase inhibitor, has received recent attention because of its ac tion on leukocytes. To clarify the effects of PTXF in reperfusion inju ry we measured the resting transmembrane potential difference (E-m) an d evaluated postcapillary venule microcirculation using intravital mic roscopy in rat skeletal muscle during ischemia and reperfusion. The in frarenal aorta was clamped for 90 min and then reperfused for 60 min. Persistent depolarization of the resting E-m was observed in an ischem ia-reperfusion (IR) group and was significantly repolarized in a PTXF group during the reperfusion period. The tissue water content was sign ificantly reduced in the PTXF group, although no difference was noted in the tissue lactate content. Flowing erythrocyte velocity and wall s hear rate in the PTXF group were significantly higher than in the IR g roup during the reperfusion period but without significant differences in vessel diameter and hemoglobin oxygenation. Blood flow measured by laser-Doppler flowmeter was also significantly improved in the PTXF g roup. Furthermore, the adherent leukocyte count was significantly redu ced in the PTXF group during this same period. These results indicate that PTXF attenuated reperfusion-associated membrane injury and tissue edema and that PTXF suppressed leukocyte adhesion and improved hindli mb blood flow during the reperfusion period.