Intestinal energy metabolism during ischemia and reperfusion

Background. In order to evaluate acute ischemic damage in the small intesti ne induced by superior mesenteric artery occlusion (SMAO) and subsequent re perfusion, changes in ATP, ADP, and AMP were measured by high-performance l iquid chromatography, and changes in tissue blood flow were measured (from the serosal surface) by the laser doppler flow meter in a rat model. Materials and methods. The superior mesenteric artery of the rat was occlud ed for 30, 60, 90, and 120 min and then reopened. Core temperature was main tained carefully at 37 +/- 0.3 degrees C. Results. All rats that underwent 90 and 120 min of SMAO died within 2 days, but those with 30 and 60 min of SMAO survived. ATP (10.39 +/- 0.90 mu mol/ g dry weight), ADP (3.34 +/- 0.33), and total adenine nucleotides (TAN; 14. 08 +/- 0.86) decreased with longer SMAO times. After 30 and 60 min of SMAO followed by reperfusion, recoveries of ATP and TAN were relatively good and ADP levels remained fairly steady, but little or no recovery of these leve ls was observed after 90 and 120 min of SMAO followed by reperfusion. There were linear correlations between the levels of ATP and TAN after 30 min of reperfusion and the time of SMAO. Tissue blood how levels were constant du ring SMAO. After reperfusion, those levels were recovered along with the SM AO periods. But recovery rates compared with control values were not relate d with those of ATP. Conclusions. ATP and TAN levels, particularly at 30 min after reperfusion, seemed to be in good agreement with the tissue damage and the viability of the small intestine. We propose that the measurement of these levels may be useful for the evaluation of intestinal damage and viability. (C) 1999 Aca demic Press.