Pituitary adenylate cyclase activating peptide, a novel VIP-like gut-brain peptide, relaxes the guinea-pig taenia caeci via apamin-sensitive potassium channels.

Authors :: Schwörer H
Katsoulis S
Creutzfeldt W
Schmidt WE
Source :: Naunyn-Schmiedeberg's archives of pharmacology [Naunyn Schmiedebergs Arch Pharmacol] 1992 Nov; Vol. 346 (5), pp. 511-4.
Publication Year :: 1992
Abstract: Effects of pituitary adenylate cyclase activating peptide (PACAP-(1-27)) and vasoactive intestinal polypeptide (VIP) on the guinea-pig taenia caeci were studied in the presence of guanethidine and scopolamine. Both peptides (1 nmol/1-1 mumol/l) concentration-dependently relaxed the smooth muscle of the taenia. PACAP-(1-27) and VIP were nearly equipotent. Apamin (30 nmol/l), a selective blocker of calcium-activated potassium channels, abolished the relaxation induced by PACAP-(1-27) whereas the effect of VIP remained unaffected. PACAP-(1-27) may be a candidate for the noncholinergic, non-adrenergic inhibitory neurotransmitter which induces apamin-sensitive relaxation in the intestinal tract.

Subjects :: Animals
Cecum drug effects
Guanethidine pharmacology
Guinea Pigs
Hexamethonium Compounds pharmacology
In Vitro Techniques
Male
Muscle Relaxation drug effects
Pituitary Adenylate Cyclase-Activating Polypeptide
Scopolamine pharmacology
Tetrodotoxin pharmacology
Vasoactive Intestinal Peptide pharmacology
Apamin pharmacology
Muscle, Smooth drug effects
Neuropeptides pharmacology
Potassium Channels drug effects

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