Stimulation of healing by free radical scavengers of ischemia-induced acute gastric mucosal injury in the rat.

Allopurinol and dimethyl sulfoxide (DMSO; 1 mL of 1, 2, or 5% by gavage daily) were used to examine the influence of scavenging oxygen-derived free radicals on the healing of reserpine- (5 mg/kg, intraperitoneal) and 5-hydroxytryptamine- (50 mg/kg, intraperitoneal) induced acute ischemic injury of the rat gastric mucosa. Allopurinol and DMSO demonstrated a time- but not dose-dependent power to stimulate healing of this injury. The magnitude of injury produced by reserpine or 5-hydroxytryptamine (serotonin) followed by gavage with allopurinol or DMSO was significantly (p < 0.01) less after day 4 than that after day 3 of this gavage, and the magnitude after day 3 was itself significantly (reserpine, p < 0.001; 5-hydroxytryptamine, p < 0.01) less than that after day 2 of the same gavage. The actions of allopurinol and DMSO were not associated with any significant influence on H+ output. These results suggest that oxygen-derived free radicals are detrimental to the integrity of the rat gastric mucosa and that scavenging them stimulates healing of the ischemia-induced injury of the mentioned mucosa.