title: Possible mechanism of acetaldehyde-induced noradrenaline release from sympathetic nerve terminals in isolated blood vessels.
abstract: 1. Vasoconstrictor responses to acetaldehyde were investigated in isolated and perfused canine intermediate auricular (ear) arteries. 2. Single injections of small doses of acetaldehyde (1-3 mumol) induced vasoconstriction in a dose-related manner and showed no tachyphylaxis. On the other hand, large doses of acetaldehyde (10-30 mumol) frequently caused tachyphylaxis when injected at 10 min intervals. 3. After tyramine treatment, constrictions induced by a large dose of acetaldehyde were consistently restored temporarily. 4. The acetaldehyde-induced vasoconstriction was inhibited by bunazosin, a potent alpha 1-adrenoceptor antagonist. 5. A small dose of imipramine blocked tyramine-induced vasoconstriction, but had no significant influence on noradrenaline (NA)-induced constrictions, and caused slight potentiation of acetaldehyde-induced constrictions. 6. Hydrocortisone treatment did not modify tyramine-induced vasoconstrictions and slightly suppressed NA- and acetaldehyde-induced constrictions but not significantly. 7. It is suggested that acetaldehyde causes a release of NA from a NA store of the sympathetic nerve terminals which is different from the tyramine-sensitive NA store, and that the acetaldehyde-sensitive NA store may be readily filled up with NA from the tyramine-sensitive store.
authors.affiliation: Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Chiba
authors.forename: M
authors.initials: M
authors.lastname: Tsukada
mesh_terms: D000079:Acetaldehyde / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D004285:Dogs; D006854:Hydrocortisone / Q000494:pharmacology; D066298:In Vitro Techniques; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000294:innervation / Q000378:metabolism*; D009411:Nerve Endings / Q000187:drug effects / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D011799:Quinazolines / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000378:metabolism*; D013618:Tachyphylaxis / Q000187:drug effects; D014439:Tyramine / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D000317:Adrenergic alpha-Antagonists; D011799:Quinazolines; C018176:bunazosin; D000079:Acetaldehyde; D006854:Hydrocortisone; D009638:Norepinephrine; D014439:Tyramine