Male Wistar rats were randomized into five groups (n聽=聽10), one sham-operated, one IR, and three postconditioned groups, each with different protocols. The animals were subjected to 60聽min of mesenteric ischemia, followed by 60聽min of reperfusion. Postconditioning was applied at the onset of reperfusion using three different algorithms. Arterial pressure and mucosal microcirculation were monitored throughout the experiment. Mesenteric pH was determined at the early phase of reperfusion. Blood and tissue samples were taken at the end of reperfusion for histologic evaluation, serum lactate dehydrogenase, serum creatine kinase, serum tumor necrosis factor-伪, serum interleukin-6, detailed mucosal antioxidant, and scavenger capacity assays.
The shorter and intermediate length cycles of postconditioning enhanced mucosal microcirculation and redox state and significantly delayed the normalization of mesenteric pH. Furthermore, milder histopathologic lesions and lower concentrations of serum necroenzymes and proinflammatory cytokines were detected compared with the IR group. The protective effect of postconditioning using longer cycles could only be seen in a tendentious manner.
In a rat model of intestinal ischemia-reperfusion, the shorter and intermediate length cycles of postconditioning proved to be more effective than the use of longer cycles.