Effect of luminal exposure of oxidants on intestinal mucosal lipid peroxidation and absorptive function

The lumen of the gastrointestinal tract is likely to have free iron and prooxidants that might generate free radicals, resulting in structural and functional damage to the absorptive cells. In the present study the effect of luminal exposure of different oxidants on intestinal mucosal lipid peroxidation and absorptive function in anaesthetized animals has been studied. Oxidants that require iron for free radical generation did not have any effect on the mucosa, whereas free radicals generated by using 2,2'azobis (2-amidino propane) dihydrochloride or menadione, which do not require iron, resulted in lipid peroxidation as assessed by malonaldehyde and conjugated diene formation and depletion of the antioxidant alpha-tocopherol. These oxidants also induced water and electrolyte secretion as studied by luminal perfusion. This observation is physiologically significant since the presence of prooxidants along with iron in the lumen may not have a damaging effect on the mucosa.