FUNCTIONAL ABLATION OF SENSORY NEURONS IMPAIRS HEALING OF ACUTE GASTRIC-MUCOSAL DAMAGE IN RATS

Healing of ethanol-injured gastric mucosa was studied in rats treated with a neurotoxic dose of capsaicin to induce functional ablation of s ensory nerves. Capsaicin treatment delayed the healing of mucosal dama ge in the glandular region and promoted the development of deep ulcera tions predominantly in the antrum. These lesions occupied 86% of the a ntral surface and were associated with marked invasion of inflammatory cells and 18-fold elevation of gastric myeloperoxidase activity compa red with vehicle-pretreated rats. Inhibition of cyclooxygenase, 5-lipo xygenase, or nitric oxide synthase did not affect the development of a ntral lesions after ethanol challenge in capsaicin-pretreated rats. In vehicle-pretreated rats, inhibition of nitric oxide synthase did not mimic the effect of functional ablation of sensory neurons. The findin gs suggest that in the gastric mucosa sensory neurons contribute to re pair processes and limit the inflammatory response to injury. These ef fects do not involve arachidonic acid metabolites or nitric oxide.