LEUKOCYTE MOBILIZATION, CHEMILUMINESCENCE RESPONSE, AND ANTIOXIDATIVECAPACITY OF THE BLOOD IN INTESTINAL ISCHEMIA AND REPERFUSION

Intestinal ischemia and reperfusion elicits changes in leukocyte count s and increased production of reactive oxygen species (ROS). The purpo se of this study was to investigate whether these changes were followe d by and/or connected with changes in the extracellular antioxidative capacity in a rat superior mesenteric artery (SMA) occlusion/reperfusi on model. The SMA was occluded for 45 min and then allowed to be reper fused. Changes of leukocyte, polymorphonuclear (PMN), and lymphocyte c ounts, chemiluminescence (CL) of whole blood samples as a marker of RO S production, and the total antioxidative capacity of the serum were q uantified at the end of ischemia and in 1 h intervals during the posti schemic period up to 4 h. The myeloperoxidase (MPO) activity in the se rum and intestinal tissue samples was also determined. The MPO activit y in the intestinal tissue samples was significantly elevated at the e nd of ischemia, and this elevation lasted for the whole postischemic p eriod. The oxidative challenge to the body induced a fast mobilization of extracellular antioxidative mechanisms already at the end of ische mia, which was followed by a significant increase in PMN counts and wh ole blood CL starting at the 2nd hour after reperfusion. The increased CL activity of whole blood was attributed to the increase of the circ ulating PMNs. No significant changes were observed in leukocyte and ly mphocyte counts. It is concluded that compensatory mechanisms of the o xidative-antioxidative balance of the body react very quickly if chall enged.