Involvement of cholinergic neurons in intestinal contraction caused by vasoactive intestinal contractor.
The mechanism of the contractile response to vasoactive intestinal contractor (VIC) was examined in the isolated guinea-pig small intestine. VIC at 10(-9) to 10(-7) M produced a transient relaxation followed by a contraction, and this contraction was partially inhibited, to the same degree, by either atropine or tetrodotoxin. VIC (10(-8) M) induced an increase in the release of [3H]acetylcholine from the ileum preloaded with [3H]choline. The VIC-induced acetylcholine release was dependent on external Ca2+. Thus, the VIC-induced contractions may relate to stimulation of cholinergic neurons and smooth muscle cells.
Department of Pharmacology II, Nagasaki University School of Medicine, Japan.
K
K
Taniyama
S
S
Kan
M
M
Yoshimura
M
M
Niwa
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002799:Cholinergic Fibers / Q000187:drug effects*; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects* / Q000294:innervation / Q000502:physiology; D066298:In Vitro Techniques; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000294:innervation / Q000502:physiology; D010455:Peptides / Q000494:pharmacology*; D013779:Tetrodotoxin / Q000494:pharmacology
D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; C059568:vasoactive intestinal constrictor; D013779:Tetrodotoxin; D001285:Atropine; D000109:Acetylcholine