a lower dose of atenolol ( 30 micrograms/kg i.v . ) markedly decreased the tachycardia in response to i.v . isoproterenol ( 2 micrograms ) but had no effect on the renal vasodilator response to intrarenal isoproterenol injection ( 2 micrograms ) , thus indicating selective beta-1 blockade .
C0039231
tachycardia
C0022245
isoproterenol