Table 2

Inhibitory effects of d-TC on α4β2 nAChRs expressed inXenopus oocytes injected with cDNAs encoding α and β subunits in the ratios indicated

α4:β2 ratioIC50nHEmax
μM % of control
9:10.20  ± 0.042-d 0.75  ± 0.02100
1:10.53  ± 0.09de 0.77  ± 0.13100
 1:12-a 0.64  ± 0.15e 0.71  ± 0.04100
 1:92-b 1.08  ± 0.75f 0.71  ± 0.1767.6  ± 8.2
163  ± 372-d 1.98  ± 0.9332.4  ± 8.2
 1:92-c 2.04  ± 0.29df 0.67  ± 0.03100

Responses were evoked by superfusion with 300 μm ACh. For each experimental condition, three concentration-effect curves, each obtained from a different oocyte, were fitted, and the values represent mean ± standard deviation of the estimated parameters.

    • 2-a Reduced receptor expression level.

    • 2-b Two-component concentration-effect curve.

    • 2-c Responses evoked by superfusion with 10 μmACh.

    • 2-d Statistical significant difference (t test; p < 0.01) between all groups indicated.

    • No statistical significant difference (t test;e p = 0.33, f p = 0.11).