title: The subdivision of beta-adrenoceptors in the cardiovascular system of the rat.
abstract: 1 The antagonism by the beta-adrenoceptor blocking drugs, propranolol (non-selective) and practolol (beta-selective), of the cardiovascular actions of isoprenaline has been investigated in the rat. 2 All doses of practolol (0.1, 1 and 3 mg/kg) blocked the cardio-accelerator action of isoprenaline but only the largest dose blocked the vasodilator effect. 3 All doses of propranolol (0.01, 0.03 and 0.1 mg/kg) blocked the vasodilator effect of isoprenaline but only the largest dose diminished the tachycardia. 4 It is concluded that in the rat, as in other species, beta-adrenoceptors may be subdivided into beta 1 (cardiac) and beta 2 (peripheral vascular) types.
mesh_terms: D000818:Animals; D002319:Cardiovascular System / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006439:Hemodynamics / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D011217:Practolol / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic / Q000145:classification*; D011943:Receptors, Adrenergic, beta / Q000145:classification* / Q000187:drug effects
chemical_list: D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D011433:Propranolol; D007545:Isoproterenol; D011217:Practolol