Capsaicin-sensitive and hexamethonium-insensitive circular muscle responses to mesenteric nerve stimulation in the isolated guinea pig ileum.
Capsaicin-sensitive and hexamethonium-insensitive contractile and relaxatory motor responses of circular muscle induced by mesenteric nerve stimulation were studied. Desensitization to substance P or to neurokinin A, or the substance P antagonist, spantide largely reduced the initial contractile response. Desensitization to calcitonin gene-related peptide moderately reduced the late prolonged relaxation response. These results indicate that both responses of the circular muscle to mesenteric nerve stimulation may be attributed to a release of neuropeptides evoked by the 'efferent' stimulation of capsaicin-sensitive sensory nerves.
Department of Physiology, Okayama University Medical School, Japan.
M
M
Takaki
J G
JG
Jin
S
S
Nakayama
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology*; D004558:Electric Stimulation; D005260:Female; D005769:Gastrointestinal Motility / Q000502:physiology*; D006168:Guinea Pigs; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology*; D007082:Ileum / Q000294:innervation / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D015288:Neurokinin A / Q000494:pharmacology; D013373:Substance P / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology
D006584:Hexamethonium Compounds; D013373:Substance P; D018738:Hexamethonium; D015288:Neurokinin A; C042867:spantide; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin