Comparison of the effects of several selective B2-receptor agonists on bronchomotor function in vitro.
Three selective B2-adrenergic stimulants were studied for their effect on the resting tone and on reversing acetylcholine (ACh)-induced bronchoconstriction in the intrapulmonary airways of rats in vitro. Neither 1-(3,5-dihydroxyphenyl)-2-[(1-[4-hydroxybenzyl]-ethyl)-amino]-ethanol-hydrobromide (Fenoterol) nor 2-tert-butylamino-1-(3,5-dihydroxyphenyl)-ethanol-sulphate (Terbutaline) had an effect on the resting tone. 4-Amino-3,5-dichlor-alpha-[(tert-butylamino)-methyl1-benzylalcohol-hydrochloride (NAB 365) caused a significant increase in the bronchial luminal diameter from control in the resting state at concentraions above 10(-5) g/ml. Only NAB 365 was effective in reversing ACh-induced bronchoconstriction in concentrations above 10(-6) g/ml. Terbutaline and Fenoterol reversed the ACh-induced bronchoconstriction only after the alpha-receptors had been blocked by phentolamine (10(-5)-10(-4)g/ml).
D000109:Acetylcholine / Q000008:administration & dosage; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D001980:Bronchi / Q000187:drug effects*; D001993:Bronchodilator Agents / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004983:Ethanolamines / Q000494:pharmacology*; D005260:Female; D005280:Fenoterol / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D010646:Phentolamine / Q000494:pharmacology; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D013726:Terbutaline / Q000494:pharmacology
D000318:Adrenergic beta-Agonists; D001993:Bronchodilator Agents; D004983:Ethanolamines; D011942:Receptors, Adrenergic, alpha; D005280:Fenoterol; D013726:Terbutaline; D000109:Acetylcholine; D010646:Phentolamine