Table 1. Pharmacological properties of distinct nAChRs.
The table shows the data of averaged fit parameters from dose-response curves of individual cells (n = number of cells). (A) α3β4 receptors (see Fig. 6 for original current traces). (B) α3β4α5 receptors. SCG neurons of β2 KO mice contain about 60 % α3β4 and 40 % α3β4α5 receptors (see Fig. 2B). (C) α3β2 receptors (see Fig. 5 for original current traces).
| A. α3β4 receptors (in the α5β2 KO) | DMPP (n = 26) | Cytisine (n = 24) | Nicotine (n = 25) | ACh (n = 24) |
|---|---|---|---|---|
| EC50 | 19.04 ± 0.76 | 34.5 ± 2.26 | 32.95 ± 1.34 | 101.4 ± 4.65 |
| Hill coefficient | 1.91 ± 0.06 | 1.44 ± 0.06 | 1.68 ± 0.06 | 1.60 ± 0.05 |
| Max current density (−pA/pF) | 107.8 ± 6.71 | 124.5 ± 9.21 | 115.6 ± 7.91 | 134.79 ± 11.21 |
| B. α3β4α5 receptors (in the β2 KO) | DMPP (n = 26) | Cytisine (n = 26) | n.d. | n.d. |
|---|---|---|---|---|
| EC50 | 23.03 ± 1.17 | 37.69 ± 2.43 | ||
| Hill coefficient | 1.79 ± 0.08 | 1.10 ± 0.02 | ||
| Max current density (−pA/pF) | 91.73 ± 6.302 | 121.12 ± 8.022 |
| C. α3β2 receptors (in the α5β4 KO) | DMPP (n = 8) | Cytisine (n = 8) | Nicotine (n = 11) | ACh (n = 10) |
|---|---|---|---|---|
| EC50 | 10.97 ± 1.79 | n.d. | 22.51 ± 1.18 | 168.73 ± 25.20 |
| Hill coefficient | 1.21 ± 0.12 | n.d. | 1.78 ± 0.18 | 0.67 ± 0.04 |
| Max current density (−pA/pF) | 39.29 ± 7.503 | 10.76 ± 1.59 %4 | 36.20 ± 8.893 | 34.29 ± 5.813 |
Not significantly different: One-way ANOVA (F = 1.742, P = 0.1636), followed by Newman-Keuls multiple comparison test (each comparison with a P > 0.05)
Significantly different (P = 0.0059, Student’s t-test)
Not significantly different: One-way ANOVA (F = 0.09781, P = 0.3429), followed by Newman-Keuls multiple comparison test (each comparison with a P > 0.05)
Cytisine at saturating concentrations produced only 10.76 ± 1.59 % of the effect of DMPP at α3β2 receptors (n = 8).