Existence of functional alpha1A- and alpha1D- but no alpha1B-adrenoceptor subtypes in rat common carotid arteries.
Using the cannula inserting method, vasoconstrictor responses to alpha1-adrenoceptor agonists (noradrenaline [NA], phenylephrine [PE] and methoxamine [ME]) and effects of alpha1-adrenoceptor antagonists (WB4101, chloroethylclonidine [CEC] and BMY7378) were investigated in isolated and perfused rat common carotid arteries. The rank order of agonist potency and efficacy was NA = PE > ME. Either WB4101 or BYM7378 inhibited NA- and PE-induced constrictions in a dose-related manner. CEC did not inhibit the NA- and PE-induced responses. The ME-induced responses were also significantly blocked by either WB4101 or BMY7378. From these results, it is concluded that there are functional alpha1A- and alpha1D-adrenoceptor subtypes in rat common carotid arteries, but no functional alpha1B subtype.
Chiba
Shigetoshi
S
Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan. Chiba@sch.md.shinshu-u.ac.jp
Tsukada
Miyoko
M
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D002339:Carotid Arteries / Q000187:drug effects* / Q000502:physiology; D003000:Clonidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004146:Dioxanes / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008297:Male; D008729:Methoxamine / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects
C547715:Adra1a protein, rat; C547718:Adra1b protein, rat; C547721:Adra1d protein, rat; D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D004146:Dioxanes; D010879:Piperazines; D018340:Receptors, Adrenergic, alpha-1; D010656:Phenylephrine; C051731:chlorethylclonidine; C010654:(2-(2',6'-dimethoxy)phenoxyethylamino)methylbenzo-1,4-dioxane; D008729:Methoxamine; C053428:BMY 7378; D003000:Clonidine; D009638:Norepinephrine