isoprenaline was both more potent and more powerful than adrenaline or noradrenaline and the increase in cyclic amp elicited by the catecholamines was powerfully antagonized by the beta-adrenoceptor antagonist propranolol but not by the alphapadrenoceptor blocker phentolamine .
C0022245
isoprenaline
C0007412
catecholamines