title: Oxprenolol and the circulation during anaesthesia in the dog: influence of intrinsic sympathomimetic activity.
abstract: Oxprenolol is a non-selective adrenergic beta-receptor antagonist displaying beta-mimetic activity. To test the hypothesis that beta-mimetic activity could minimize the response of the circulation to adrenergic beta-receptor blockade, cumulative dose-response curves to oxprenolol 0.1-1.6 mg kg-1 were obtained in seven anaesthetized dogs. Anaesthesia was maintained with 0.5% halothane supplementing nitrous oxide 66% in oxygen, under moderately hypocapnic IPPV. Oxprenolol, up to 0.4 mg kg-1 i.v., caused modest increases in heart rate, LV dP/dt max and cardiac output. With the largest dose (1.6 mg kg-1), significant increases in heart rate (+19%), LV dP/dt max (+13%) and cardiac output (+27%) were observed while arterial pressure remained unchanged and systemic vascular resistance decreased (-18%).
mesh_terms: D000769:Anesthesia, Inhalation; D000818:Animals; D003864:Depression, Chemical; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006221:Halothane; D006439:Hemodynamics / Q000187:drug effects*; D007545:Isoproterenol / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects; D009609:Nitrous Oxide; D010096:Oxprenolol / Q000494:pharmacology*; D013268:Stimulation, Chemical
chemical_list: D010096:Oxprenolol; D009609:Nitrous Oxide; D007545:Isoproterenol; D006221:Halothane