the concentrations giving half-maximal effectiveness ( ec50 ) were about 2 x 10 ( -8 ) m , 3 x 10 ( -8 ) m , 8 x 10 ( -8 ) m , and 5 x 10 ( -7 ) m for isoproterenol , dopamine , norepinephrine , and epinephrine , respectively .
C0028351
norepinephrine
C0014563
epinephrine