Sodium nitrite, a nitric oxide (NO) donor in the acid pH, has been found to mitigate lipid peroxidation in rat gastric mucosa, and it elevated both Cu, Zn- and Mn-forms of the superoxide dismutase in this tissue. Putrescine, a simple p oly amin e of anti-oxidant properties has been shown to normalize lipid peroxidation levels in nitrite-treated animals.