title: Beta-adrenoceptor blocking properties and cardioselectivity of M & B 17,803A.
abstract: 1. The beta-adrenoceptor blocking properties of (+/-)-1-(2-acetyl-4-n-butyramidophenoxy)-2-hydroxy-3-isopropylaminopropane hydrochloride (M&B 17,803A) have been compared with those of practolol and propranolol in the guinea-pig, cat and dog.2. Following either intravenous or oral administration in the cat or dog, M&B 17,803A and practolol had similar potency in antagonizing isoprenaline-induced tachycardia and both showed cardioselectivity, but both were less potent than propranolol.3. M&B 17,803A and practolol had approximately one hundredth the intravenous potency of propranolol in increasing the severity of anaphylactic bronchospasm in the conscious sensitized guinea-pig.4. M&B 17,803A possessed less marked intrinsic sympathomimetic activity than practolol but, like propranolol, it had significant local anaesthetic properties and increased the refractory period of rabbit isolated atria.
mesh_terms: D000083:Acetanilides / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000605:Amino Alcohols / Q000494:pharmacology; D000707:Anaphylaxis / Q000139:chemically induced; D000772:Anesthesia, Local; D000813:Anilides / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001980:Bronchi / Q000187:drug effects; D002415:Cats; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography; D004983:Ethanolamines / Q000494:pharmacology*; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D007545:Isoproterenol / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011437:Propylamines / Q000494:pharmacology; D011930:Reaction Time / Q000187:drug effects
chemical_list: D000083:Acetanilides; D000319:Adrenergic beta-Antagonists; D000605:Amino Alcohols; D000813:Anilides; D004983:Ethanolamines; D011437:Propylamines; D011433:Propranolol; D007545:Isoproterenol