Laparotomy-induced gastric protection against ethanol injury is mediated by capsaicin-sensitive sensory neurons.
Laparotomy significantly attenuates ethanol-induced gastric mucosal lesions in the rat. The effects of sensory denervation by capsaicin, indomethacin, atropine, guanethidine, and hexamethonium on laparotomy-induced protection were studied in the rat. Gastric mucosal injury was induced by the intragastric instillation of 1 mL of 75% ethanol. The laparotomy-induced protection against ethanol injury was abolished by sensory denervation by capsaicin (total dose, 125 mg/kg, SC) and also by pretreatment with indomethacin (5 mg/kg, SC). In contrast, pretreatment with atropine (0.5 mg/kg, IP), guanethidine (total dose, 20 mg/kg, SC), or hexamethonium (20 mg/kg, IP) had no significant effect on laparotomy-induced protection. These data indicate that capsaicin-sensitive sensory afferent neurons, but not cholinergic or adrenergic autonomic neurons, mediate laparotomy-induced protection against ethanol injury. The hypothesis is put forward that the protective response to laparotomy arises from a somatovisceral and/or viscerovisceral axon reflex of capsaicin-sensitive afferent neurons. Prostaglandins might play a mediator role in the activation by laparotomy of somatic and/or visceral branches of the afferent neurons.
Yonei
Y
Y
Medical Service, Veterans Administration Medical Center West Los Angeles, California.
Holzer
P
P
Guth
P H
PH
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology*; D000431:Ethanol / Q000633:toxicity*; D005730:Ganglionic Blockers / Q000494:pharmacology; D005753:Gastric Mucosa / Q000187:drug effects*; D006145:Guanethidine / Q000494:pharmacology; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D007813:Laparotomy; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains
D005730:Ganglionic Blockers; D006584:Hexamethonium Compounds; D018738:Hexamethonium; D000431:Ethanol; D001285:Atropine; D002211:Capsaicin; D007213:Indomethacin; D006145:Guanethidine