Estimates of xanomeline pKB in antagonizing the responses to carbachol
Negative logarithms of xanomeline pKB based on its effect on carbachol-stimulated [35S]GTPγS binding. Constants were obtained by nonlinear regression of eq. 5 to EC50 of carbachol concentration-response curves from individual experiments. Table shows averages ± S.E.M. (n = 4). Values of pEC50 of xanomeline concentration-response curves and pKI of xanomeline inhibition of [3H]NMS binding are shown for comparison.
| M1 | M2 | |||||
|---|---|---|---|---|---|---|
| pKB | pEC50 | pKI | pKB | pEC50 | pKI | |
| Without preincubation | 8.08 ± 0.04* | 8.04 ± 0.01* | 7.87 ± 0.04 | 7.37 ± 0.03 | N.E. | 7.43 ± 0.04 |
| 60-min preincubation | 8.15 ± 0.02† | 8.15 ± 0.04† | N.M. | 7.77 ± 0.04† | 7.78 ± 0.03 | N.M. |
| 60-min preincubation followed by washing | 5.69 ± 0.04*‡ | 5.98 ± 0.03* | 6.53 ± 0.05 | 4.78 ± 0.03*‡ | 5.81 ± 0.03* | 6.53 ± 0.05 |
N.E., no effect; N.M., not measured.
↵* Significantly different from corresponding pKI by ANOVA followed by Tukey-Kramer post-test.
↵† Significantly different from without preincubation by ANOVA followed by Tukey-Kramer post-test.
↵‡ Significantly different from corresponding pEC50 by ANOVA followed by Tukey-Kramer post-test.