Relationship between time of reperfusion and E-selectin expression, neutrophil recruitment, and germ cell apoptosis after testicular ischemia in a rat model

Objective To examine the relationship between the time of reperfusion and neutrophil recruitment, E-selectin expression, and germ cell apoptosis in the ischemic and contralateral testis after testicular ischemia-reperfusion (IR) injury in a rat. Design Laboratory study. Setting Research laboratory in a faculty of medicine at Technion–institute of technology in Israel. Animal(s) Sixty adult Sprague-Dawley rats weighing 250–280 g. Intervention(s) Testicular IR. Main Outcome Measure(s) Testicular germ cell apoptosis was assessed by terminal deoxynucleotide transferase–mediated 2′-deoxyuridine 5′-triphosphate nick-end labeling immunohistochemical assay, using an in situ cell death detection kit. The recruitment of polymorphonuclear (PMN) cells was calculated per 100 venules. Expression of E-selectin was determined by using immunohistochemical analysis. Result(s) E-selectin expression and polymorphonuclear-cell recruitment in the contralateral testis increased significantly after 1 hour of reperfusion and then remained unchanged during the first 24–48 hours, followed by a gradual decrease. Germ cell apoptosis in the contralateral testis increased after 6 hours of reperfusion, achieved statistical significance after 24 hours, and decreased after 72 hours of reperfusion. Conclusion(s) Germ cell apoptosis in the contralateral testis increases most significantly within the first 24–48 hours, followed by a gradual decrease, after IR injury. E-selectin expression and neutrophil recruitment increases within the first 6 hours and apparently may initiate the increase in germ cell apoptosis.