In vivo observation of leukocyte-endothelium interaction in ischemia reperfusion injury with the dorsal window chamber and the effects of pentoxifylline on reperfusion injury.

Abstract

OBJECTIVE: Ischemia reperfusion injury can cause failure in microsurgical operations. Interaction between leukocytes and endothelium is recognized as an integral step in ischemia reperfusion injury. Pentoxifylline is a methylxanthine derivative that has pharmacological properties that can be beneficial in ischemia reperfusion injury. The aim of this study was to investigate the in vivo effect of pentoxifylline on leukocyte-endothelium interaction in ischemia reperfusion injury. METHODS: Intravital fluorescent microscopy was used to observe leukocyte-endothelium interaction in a "dorsal window chamber" model. Twenty-eight postcapillary veins were analyzed in group 1, and twenty-two in group 2. Group 1 received 25 mg/kg pentoxifylline 20 min before reperfusion. Group 2 received an equivalent volume of 0.9% saline at the same time. The period of ischemia was 4 h. RESULTS: Quantification of leukocyte 'sticking' and 'rolling' was done before ischemia and at 30, 60, and 120 min after reperfusion. Offline video analysis was used for evaluating the results. Statistical evaluation showed that pentoxifylline significantly attenuated leukocyte 'sticking' and 'rolling' in postcapillary venules. It was also effective in preventing 'no-reflow' when compared with the control group. CONCLUSION: These results indicate pentoxifylline diminishes leukocyte-endothelium interaction, and may have a therapeutic role in preventing ischemia reperfusion injury in microsurgical operations.