TABLE 1

Comparison of pEC50 values (top) and Emax values (bottom) relative to L755507 for responses in functional bioassays in CHO-K1 cells expressing human β3-adrenoceptors (CHOhβ3)

Note the relatively low Emax value for L748337 for cAMP accumulation but that the same compound has high Emax values for ECAR, p38 MAPK, and Erk1/2 activation. Agonist potency values are mean ± S.E.M. (n).


Ligand

cAMP

ECAR

p38 MAPK

Erk1/2

pKi Binding
Zinterol 7.1a
pEC50 (n) 8.55 ± 0.09 (4) 8.14 ± 0.05 (4) 5.93 ± 0.19 (6) 10.86 ± 0.18 (5)
Emax relative to L755507b 1.02 0.96 0.60 0.75
L755507 7.9c
pEC50 (n) 12.28 ± 0.03 (4) 8.64 ± 0.08 (4) 5.54 ± 0.34 (4) 11.72 ± 0.31 (6)
Emax relative to L755507b 1.00 1.00 1.00 1.00
L748337 8.4d
pEC50 (n) 9.12 ± 0.82 (4) 7.15 ± 0.06 (4) 5.66 ± 0.29 (4) 11.58 ± 0.33 (6)
Emax relative to L755507b
0.11
0.95
1.42
0.90

  • a Data from Hutchinson et al. (2006).

  • b Defined as a fraction of the absolute maximal response to L755507 in each individual experiment.

  • c Data from Fischer et al. (1998).

  • d Data from Candelore et al. (1999).