Table 1.
Schild plot results for carbachol with various antagonist dissociation constants (KB2 and KB3, nM) at muscarinic M2 and M3 receptors if the interaction were additive. The agonist dissociation constants were fixed at the values used in example 1, viz., KA2 = 2.75 and KA3 = 62.0 (nM) whereas the antagonist K’s are varied as indicated. For each of the four cases shown a Schild analysis was made in the usual (linear) way, thereby providing the line’s slope and pA2 value. The apparent K listed in each case is the antagonist dissociation constant (nM) calculated from the derived pA2.
KB2 | KB3 | Slope | pA2 | Kapparent |
---|---|---|---|---|
0.1 | 100 | 0.854 | 7.38 | 41.7 |
1.0 | 100 | 0.881 | 7.33 | 46.8 |
100 | 0.1 | 1.00 | 9.94 | 0.115 |
100 | 1.0 | 0.999 | 8.94 | 1.15 |