Isoprenaline- and exercise- induced tachycardia in the assessment of beta-adrenoceptor blocking drugs; a comparison between tolamolol, practolol and propranolol.
The effects of tolamolol, propranolol and practolol on both isoprenaline- and exercise-induced tachycardia have been studied in conscious dogs. Tolamolol was approximately equipotent to propranolol and 50 times more potent than practolol in antagonizing exercise-induced tachycardias, but was approximately 12 times less potent than propranolol and 8 times more potent than practolol in blocking isoprenaline-induced tachycardia. It is suggested that antagonism of the tachycardia induced by exercise affords a more meaningful assessment of the possible therapeutic potential of beta-adrenoceptor blocking drugs than does that induced by isoprenaline.
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D003408:Cresols / Q000494:pharmacology; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D007545:Isoproterenol / Q000494:pharmacology*; D008722:Methods; D005082:Physical Exertion; D011217:Practolol / Q000494:pharmacology*; D011412:Propanolamines / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology*; D013268:Stimulation, Chemical
D000319:Adrenergic beta-Antagonists; D001549:Benzamides; D003408:Cresols; D011412:Propanolamines; D011433:Propranolol; D007545:Isoproterenol; D011217:Practolol