title: Blockade of different subtypes of α(1)-adrenoceptors produces opposite effect on heart chronotropy in newborn rats.
abstract: We compared the effects of blockade of α(1A)-, α(1B)-, and α(1D)-subtypes of α(1)-adrenoceptors on the cardiac rhythm in newborn rats. Different responses of the heart were observed after blockade of several subtypes of α(1)-adrenoceptors. Administration of WB 4101, a selective blocker of α(1A)-adrenoceptors, increased heart rate, while blockade of α(1AD)-adrenoceptors with BMY 7378 decelerated of heart rhythm. Blockade of α(1B)-adrenoceptors with chloroethylclonidine produced no significant effects on heart chronotropy.
authors: Department of Anatomy, Physiology, and Human Health Protection, Kazan (Privolzhskii) Federal University, Russia.
authors: N I
authors: NI
authors: Ziyatdinova
authors: R E
authors: RE
authors: Dementieva
authors: L I
authors: LI
authors: Fashutdinov
authors: T L
authors: TL
authors: Zefirov
mesh_terms: D058668:Adrenergic alpha-1 Receptor Antagonists / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D003000:Clonidine / Q000031:analogs & derivatives / Q000494:pharmacology; D004146:Dioxanes / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*
chemical_list: D058668:Adrenergic alpha-1 Receptor Antagonists; D004146:Dioxanes; D010879:Piperazines; D018340:Receptors, Adrenergic, alpha-1; C051731:chlorethylclonidine; C010654:(2-(2',6'-dimethoxy)phenoxyethylamino)methylbenzo-1,4-dioxane; C053428:BMY 7378; D003000:Clonidine