Effect of omeprazole on acute gastric stress ulceration in cervical cord transected rats

Patients with acute paraplegia from trauma have an increased frequency of developing gastric stress ulceration and subsequent hemorrhage. Current treatment of gastric stress ulcer is by antacids or H2 antagonists, but despite such therapy stress ulceration still occurs, probably because these agents are unable to maintain gastric pH above 4. Omeprazole, which blocks the terminal step of acid secretion--the proton pump, can produce long-lasting achlorhydria. This study examined the efficacy of omeprazole in preventing stress ulcer in rats with acute cervical cord transection. Omeprazole was administered intraduodenally at 1.725, 2.625, 3.5, and 17.5 mg/kg, and the ulcer incidence and gastric acid output were measured. Omeprazole produced a dose-dependent inhibition of gastric acid output in the cervical cord transected rat. At the highest dose, complete achlorhydria was achieved. The quantity of gastric ulceration was inversely proportional to the omeprazole dosage with nearly complete prevention of ulceration at the highest dose. In conclusion, omeprazole is very effective in preventing gastric stress ulcers in the spinal cord transected rat. This appears to be related to its potent long-lasting inhibitory effect on gastric acidity.