SELECTIVITY OF β-ADRENOCEPTOR AGONISTS AND ANTAGONISTS ON BRONCHIAL, SKELETAL, VASCULAR AND CARDIAC MUSCLE IN THE ANAESTHETIZED CAT

摘要: 1 The potencies of fifteen beta-adrenoceptor agonists widely differing chemical structures were compared with that (-)-isoprenaline on bronchial muscle, soleus blood pressure and heart rate in the anaesthetized cat. antagonist propranolol practolol determined against same model. 2 (-)-Isoprenaline was most potent agonist its action essentially unselective. Thus, all four parameters minimal effective dose 0.003-0.01 mug/kg maximal or near responses produced by 0.3-1 mug/kg. Trimetoquinol also an unselective agonist. 3 For thirteen remaining fourteen agonists, potency similar muscle but significantly lower rate. 4 - AH 7616 (4-hydroxy-alpha1-[[(1-methyl-3,3-diphenyl-propyl)amino]-methyl]-m-xylene-alpha1, alpha3-diol, acetate) less than other parameters; addition, it clearly when 5-hydroxytryptamine (5-HT) used to induce bronchospasm. However, acetylcholine instead 5-HT very similar. may therefore possess a specific addition action. 5 test longer acting this particularly true trimetoquinol soterenol. 6 almost identical slightly heart. Practolol 10-12 times more pressure. 7 These findings suggest not be possible separate bronchodilating tremorenhancing properties agonists. results antagonists are accord Lands' dual sub-classification.