Postischemic accumulation of the lipid peroxidation product 4-hydroxynonenal in rat small intestine.

4-Hydroxynonenal (HNE) as an indicator of lipid peroxidation was determined in rat jejunal mucosa. HNE was extracted as the dinitrophenylhydrazone derivative from the tissue, partially separated from other carbonyl compounds by thin-layer chromatography and measured by HPLC. During reperfusion of the small intestine following an ischemic period of 60 minutes a marked increase of the tissue concentration of HNE was observed. The mucosal HNE level passed a maximum value of 3.0 +/- 0.5 microM 10 min after the onset of reperfusion in comparison with 0.7 +/- 0.2 microM as initial value. The increased tissue level of the highly cytotoxic 4-hydroxyalkenal is suggested to be involved in the reperfusion induced morphological and biochemical changes of the small intestine.