Table 1

Affinity of ligands for [3H]-mepyramine and [3H]-(−)-trans-H2-PAT labeled H1receptors in CHOgpH1 and CHOhuH1 cell membranes

LigandCHOgpH1K0.5CHOhuH1K0.5
vs. [3H]-MepyraminenHvs. [3H]-(−)-trans-H2-PATnHvs. [3H]-MepyraminenHvs. [3H]-(−)-trans-H2-PATnH
nM nM
Doxepin0.28  ± 0.011.04  ± 0.070.16  ± 0.021.16  ± 0.150.32  ± 0.011.15  ± 0.060.09  ± 0.010.91  ± 0.09
Mepyramine0.57  ± 0.010.84  ± 0.030.74  ± 0.051.05  ± 0.041.18  ± 0.101.05  ± 0.071.01  ± 0.041.13  ± 0.13
Triprolidine0.93  ± 0.160.92  ± 0.080.69  ± 0.071.06  ± 0.101.53  ± 0.120.98  ± 0.021.11  ± 0.061.03  ± 0.12
(+)-Chlorpheniramine1.98  ± 0.160.97  ± 0.040.69  ± 0.100.93  ± 0.024.81  ± 0.050.99  ± 0.062.67  ± 0.230.92  ± 0.06
(−)-Chlorpheniramine98.0  ± 1.00.96  ± 0.0680.1  ± 7.40.92  ± 0.04361  ± 401.03  ± 0.07211  ± 90.91  ± 0.07
Diphenhydramine9.20  ± 0.810.87  ± 0.019.57  ± 0.791.31  ± 0.0413.5  ± 1.00.97  ± 0.0411.7  ± 0.750.89  ± 0.11
Clozapine1.23  ± 0.030.98  ± 0.022.07  ± 0.131.29  ± 0.201.63  ± 0.151.07  ± 0.181.54  ± 0.111.27  ± 0.13
(−)-trans-H2-PAT1.15  ± 0.360.87  ± 0.140.58  ± 0.100.96  ± 0.032.50  ± 0.170.91  ± 0.091.65  ± 0.140.98  ± 0.11
(±)-trans-H2-PAT1.53  ± 0.060.98  ± 0.031.37  ± 0.040.95  ± 0.114.26  ± 0.250.89  ± 0.072.49  ± 0.270.98  ± 0.13
(+)-trans-H2-PAT23.0  ± 2.01.03  ± 0.0611.54  ± 0.131.14  ± 0.1542.4  ± 1.61.04  ± 0.0629.9  ± 4.71.02  ± 0.09
(−)-cis-H2-PAT3.92  ± 0.180.86  ± 0.074.91  ± 0.031.03  ± 0.088.91  ± 0.760.89  ± 0.086.31  ± 0.230.92  ± 0.05
(±)-cis-H2-PAT10.89  ± 0.141.00  ± 0.027.87  ± 0.631.14  ± 0.0213.6  ± 0.80.88  ± 0.0214.7  ± 0.461.00  ± 0.01
(+)-cis-H2-PAT53.79  ± 1.390.97  ± 0.0477.7  ± 1.071.23  ± 0.18129  ± 130.87  ± 0.07122  ± 91.00  ± 0.13
Histamine18.3  ± 1.2 μM0.72  ± 0.099.9  ± 0.9 μM0.65  ± 0.0513.5  ± 0.8 μM0.67  ± 0.0110.5  ± 0.6 μM0.72  ± 0.03
+1 mM GTP25.0  ± 1.5 μM0.85  ± 0.0917.6  ± 0.9 μM0.78  ± 0.09N.D.N.D.
  • N.D., not determined.