TABLE 3

Histamine H3 receptor ligand potencies and relative efficacies for the inhibition of RAMH-mediated stimulation of calcium mobilization, as detected using FLIPR or for reversal of RAMH-mediated inhibition of FSK-stimulated cAMP levels (cyclase) Due to minimal or no antagonist response, statistics were not calculated for imetit.



G α Subunit Expressed

FLIPR

Cyclase

pIC50
Relative Efficacy
pIC50
Relative Efficacy
Clobenpropit G16 7.41b,c,d 1.00c,d 6.79b 1.00
Gq/i5 7.10c,d 1.00c,d 6.55b 0.92
Ciproxifan G16 6.57a,c 0.97c,d 5.39a 0.96
Gq/i5 6.58c,d 1.00c,d 5.30a 1.00
GT-2331 G16 5.74a,b 0.50a,b N.D. N.D.
Gq/i5 5.26a,b,d 0.34a,b N.D. N.D.
Proxyfan G16 620a 0.56a,b N.D. N.D.
Gq/i5 5.89a,b,c 0.36a,b N.D. N.D.
Imetit G16 6.94 0.19

Gq/i5
N.D.
N.D.


  • N.D., not detectable; —, not determined.

    Values significantly different from aclobenpropit, bciproxifan, cGT-2331, and dproxyfan within assay type and equivalent G protein (P < 0.05).