Parameters for the interaction of strychnine with [3H]NMS and ACh at m1—m5 muscarinic receptors
| Subtype | Assay | Log affinity | Cooperativity | n | ||
|---|---|---|---|---|---|---|
| Unoccupied receptor | [3H]NMS-occupied receptor | [3H]NMS | ACh | |||
| m1 | Nonequilibrium | 5.13 | 5.00 | 0.8 | 0.32 | |
| Equilibrium | 4.90 | 4.90 | 1.0 | 0.41 | ||
| m2 | Nonequilibrium | 4.86 | 5.24 | 2.4 | 0.05 | |
| Equilibrium | 4.96 | 5.28 | 2.2 | 0.15 | ||
| m3 | Nonequilibrium | |||||
| Equilibrium | 4.16 | 4.02 | 0.7 | <0.1 | ||
| m4 | Nonequilibrium | 4.78 | 5.07 | 1.8 | 0.14 | |
| Equilibrium | 5.01 | 5.23 | 1.7 | 0.46 | ||
| m5 | Nonequilibrium | |||||
| Equilibrium | 3.87 ± 0.05 | 3.05 ± 0.04 | 0.15 ± 0.01 | <0.01 | 2 | |
Values at m1—m4 receptors are from Lazareno and Birdsall (1995).