Intraportal acetylcholine administered to narcotized rats produced atropine-resistant constriction of hepatic veins, which was considerably prevented by phentolamine. Sodium nitroprusside produced a vasodilator effect. Similar results were obtained on isolated venous strip from the portal vein: acetylcholine-induced contraction was reduced by 25-50% in the presence of nicotinic receptor antagonist tubocurarine and cholinergic agonist nicotine and by 10% in the presence of tetrodotoxin. Probably, acetylcholine stimulates synthesis and release of a vasoconstrictor transmitter via nicotinic receptors of endothelial cells and/or portal vascular wall nerve terminals.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.