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.