Pretreatment with remote ischemic conditioning attenuates testicular damage after testicular ischemia and reperfusion injury in rats

Abstract

Testicular torsion is a urological emergency. However, surgical detorsion of the torsed spermatic cord can cause testicular reperfusion injury. Although remote ischemic preconditioning (RIPC) has been convincingly shown to protect organs against ischemia/reperfusion (I/R) injury, little is known regarding the effect of RIPC on testicular torsion/detorsion-induced reperfusion injury. Therefore, we aimed to evaluate the effect of RIPC on testes after testicular I/R injury in a rat model in vivo. Male Sprague–Dawley rats were randomly classified into 4 groups: sham-operated (sham), testicular I/R (TI/R), or remote liver (RIPC liver) and limb (RIPC limb) ischemic preconditioning groups. Testis I/R was induced by 3 h of right spermatic cord torsion (720° clockwise), and reperfusion was allowed for 3 hours. In the RIPC group, four cycles of 5 min of ischemia and 5 min of reperfusion were completed 30 min prior to testicular torsion. The ERK1/2 inhibitor U0126 was administered intravenously at the beginning of reperfusion (1 mg/kg). The testes were taken for the oxidative stress evaluations, histology, apoptosis, immunohistochemical and western blotting analysis. Remote liver and limb ischemic preconditioning attenuated ipsilateral and contralateral testicular damage after testicular I/R injury. For example. RIPC reduced testicular swelling and oxidative stress, lessened structural damage, and inhibited the testicular inflammatory response and apoptosis. Furthermore, RIPC treatment enhanced testicular ERK1/2 phosphorylation postI/R. Inhibition of ERK1/2 activity using U0126 eliminated the protection offered by RIPC. Our data demonstrate for the first time that RIPC protects testes against testicular I/R injury via activation of the ERK1/2 signaling pathway.