when incubations are performed for 15 s at 37 degrees c , the affinity is more than 100-fold higher than that obtained in equilibrium ( 45 min ) assays ( ic50 = 28 +/- 3 vs 5300 +/- 400 nm for ( - ) -epinephrine and 32 +/- 3 vs 6100 +/- 500 nm for ( - ) -norepinephrine ) .
C0014563
epinephrine
C0028351
norepinephrine