Implication of sensory neurons in the diverse mechanisms of adaptive cytoprotection in the rat stomach.

Adaptive cytoprotection is mediated by diverse mediators and mechanisms. We investigated the implication of capsaicin-sensitive afferent neurons in the adaptive cytoprotection in the rat stomach, taking special notice of nitric oxide, prostaglandins and luminal dilution. Sensory deafferentation abolished the protective effect of capsaicin against 0.6 N HCl-induced gastric injury but not the indomethacin-resistant or NG-nitro-L-arginine-resistant adaptive cytoprotection conferred by 0.1 N NaOH. Nor did it attenuate the protection by 0.35 N HCl which accompanied luminal dilution. These findings suggest that certain mild irritants do not require sensory neurons to provide nitric oxide- and prostaglandins-mediated adaptive cytoprotection and, furthermore, that capsaicin-sensitive afferent neurons are not crucial, either, so long as there is a contribution of luminal dilution in the adaptive cytoprotection.