title: Clonidine and noradrenaline fail to inhibit vagal induced bradycardia. Evidence against prejunctional alpha-adrenoceptors on vagal varicosities in guinea pig right atria.
mesh_terms: D000818:Animals; D003000:Clonidine / Q000494:pharmacology*; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D013997:Time Factors; D014630:Vagus Nerve / Q000502:physiology*
chemical_list: D011942:Receptors, Adrenergic, alpha; D011433:Propranolol; D003000:Clonidine; D009638:Norepinephrine; D010646:Phentolamine