in order to localize the main site of action of the beta 2-adrenoceptor selective agonist terbutaline and the beta 1-adrenoceptor selective antagonist atenolol in the airways of asthmatic patients , we compared the effects of these drugs on maximal expiratory flow-volume ( mefv ) curves when breathing air and when breathing a helium-oxygen ( heo2 ) mixture .
C0039542
terbutaline
C0004096
asthmatic