the beta-action of catecholamines on the smooth muscle of guinea-pig taenia coli was investigated by observing the effects of isoprenaline ( 2 x 10 ( -8 ) -7.2 x 10 ( -6 ) m ) in the presence of an alpha-blocker , phentolamine ( 6.3 x 10 ( -6 ) m ) .
C0007412
catecholamines
C0022245
isoprenaline