when t3 ( 10 pg/min , 40 pg/min , 0.1 microgram/min , or 0.4 microgram/min ) was continuously infused into the sinus node artery , both positive chronotropic and inotropic actions of norepinephrine ( 0.03 microgram -- 0.3 microgram ) were not influenced .
C1372804
positive chronotropic
C0028351
norepinephrine