Kinetics of chemoluminiscence of rat intestine during ischemia and reperfusion

: Oxygen free radicals are involved in ischemic and reperfusion tissular injuries. Chemiluminescence of organs reflects the steady state level of peroxy radicals, usually generated by oxygen radicals. In this study, chemiluminescence of intestine has been determined in rats subjected to 2, 5 or 10 min of occlusive ischemia by ligation. During the ischemic period, chemoluminescence tends to decrease. After delegation, a constant response, a chemiluminescence overshoot, can be obtained only in the group of rats subjected to 2 min of ligation. This methodology does not provide constant results with longer periods of ligation. In other groups of rats subjected to 2 min of ligation and then delegated, the kinetics of the organ emission in function of time show a mean overshoot of about 44% after 3 min of reperfusion. This early excess of chemiluminescence is maintained for the first 10 to 20 min after delegation, but not for longer periods. The administration of a free radical scavenger, thioctic acid 100 mg/kg i.p., prevents or reduces the amount of the overshoot previously described during the 20 min postdelegation follow-up period. These data suggest that excessive oxygen radical generation occurs in vivo during the early minutes of reperfusion and may be the consequence of very fast enzymatic changes during the short-term previous hypoxic period. Further studies are needed to demonstrate the subsequent functional alteration and the pathological implication of this phenomenon.