The. effects of preconditioning on the oxidative stress in small-bowel autotransplantation

Background. One determining factor in intestinal transplantation is the extreme sensitivity of the small bowel to ischemia-reperfusion injury. This study investigated the effect of ischemic preconditioning prior to autotransplantation. Methods. Total orthotopic intestinal autotransplantation was performed in 40 mongrel dogs. In 4. groups (GI-GIV), grafts were stored for 3 hours in cold Euro Collins (GI, GIII) and University of Wisconsin (GII, GIV) solutions. In GIII and GIV, before preservation, preconditioning was induced by 4 cycles (5-min ischemia + 10-min reperfusion). Bowel samples were collected after laparotomy (control), at the end of preservation and reperfusion periods. We determined oxidative stress markers (reduced glutathione [GSH], superoxide dismutase [SOD]), production of oxygen free radicals, activity of nuclear factor-kappaB (NF-kappaB), and DNA damage. Results. In the non-preconditioned groups, GSH concentration increased slightly, while SOD activity decreased significantly during reperfusion. In the preconditioned groups, GSH increased markedly, and better preservation of SOD was observed. The number of oxygen free radicals increased during reperfusion mainly in non-preconditioned groups. Activation of NF-kappaB peaked by 1 hour, and decreased 3 hours after preconditioning. We observed DNA-damaged cells in all groups. Conclusions. Our findings confirm that preconditioning prior to preservation can moderate the severity, Of oxidative stress and activate the endogenous cellular adaptation in bowel tissue.