Specific receptor for vasoactive intestinal contractor in myenteric cholinergic neurones.
The receptor for vasoactive intestinal contractor (VIC) involved in acetylcholine release was examined in the guinea-pig ileum. VIC (10(-9) to 10(-7) M) evoked tritium outflow from ileal strips preloaded with [3H]choline, in a concentration-dependent manner. The evoked tritium outflow was Ca(2+)-dependent and tetrodotoxin-sensitive, suggesting that VIC acts on somato-dendritic regions of the cholinergic neurones to stimulate acetylcholine release. The response to VIC did not change after desensitization to either endothelin-1, endothelin-2 or endothelin-3, hence there is probably no cross-desensitization in evoked tritium outflow between VIC and endothelins. VIC-induced contractions consisted of tetrodotoxin-sensitive and -resistant contractions, and the tetrodotoxin-resistant contraction was abolished after desensitization to either endothelin-1, endothelin-2 or endothelin-3. These results indicate that the VIC-specific receptor is located on cholinergic neurones, but not on the smooth muscle cells of guinea-pig ileum.
Kan
S
S
Department of Pharmacology II, Nagasaki University School of Medicine, Japan.
Niwa
M
M
Taniyama
K
K
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016232:Endothelins / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects / Q000294:innervation / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects; D009474:Neurons / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D018000:Receptors, Peptide / Q000187:drug effects / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology
D016232:Endothelins; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D018000:Receptors, Peptide; C059568:vasoactive intestinal constrictor; C071686:vasoactive intestinal contractor receptor; D013779:Tetrodotoxin; D000109:Acetylcholine; D002118:Calcium