using this displacement technique , we were able to calculate the dissociation constants for l-epinephrine , l-norepinephrine , and l-isoproterenol from the beta-receptor and compare these values to the apparent dissociation constants obtained from the direct activation of adenylate cyclase ( ec 4.6.1.1 ) by these catecholamines .
C0014563
epinephrine
C0028351
l-norepinephrine