Quantification of neutrophil adhesion to skeletal muscle venules following ischemia-reperfusion.

Ischemia-reperfusion is encountered in a wide variety of surgical situations. The damage resulting from ischemia-reperfusion may be due, in part, to the infiltration and activation of neutrophils into the reperfused tissue. The purpose of the study was to examine ischemia-reperfusion induced neutrophil activation in skeletal muscle. In control muscles, ischemia in the hamster right cremaster muscle was produced for 5 min after an initial 2 hr 55 min perfusion period. In ischemic muscles, ischemia was produced for 3 hr prior to reperfusion. After the clamps were removed, a video recording of the cremaster microvasculature was made using intravital fluorescence microscopy. Acridine orange was infused intravenously 10 min prior to video recording in order to selectively label and enhance the contrast of neutrophils. The number of neutrophils rolling along the endothelium of 40 to 60 microns-diameter venules in a 1-min period increased from 9.0 in control animal cremaster venules to 24.1 following ischemia-reperfusion (p less than .05; n = 11). The ischemia-reperfusion model developed in this study allows for the direct quantification of neutrophil adhesion in skeletal muscle and can be further used to assess pharmacologic minimization of neutrophil-mediated damage in skeletal muscle.