Parameters for agonist and/or antagonist action at hα 4β 2-nA ChR.
86Rb+ efflux assays were conducted as described under Materials and Methods and in the legends to Figs. 7 and 8. Results were fit to the logistic equation to determine log EC50 values (for agonists) or IC50 values (for antagonists) and Hill coefficients (presented ± S.E.M.). Functional log IC50 values and Hill numbers given in parentheses for nicotine and suberyldicholine are from fits to the self-inhibitory phase of agonist dose-response profiles for those drugs.
| Drug | log EC50 | nh | log IC50 | nh |
|---|---|---|---|---|
| Epibatidine | −8.07 ± 0.08 | 1.12 ± 0.22 | ||
| Nicotine | −6.07 ± 0.21 | 0.79 ± 0.21 | (−2.24 ± 0.93) | (−0.76 ± 1.15) |
| Cytisine | −5.90 ± 0.32 | 0.67 ± 0.31 | ||
| Suberyldicholine | −5.89 ± 0.19 | 1.15 ± 0.39 | (−3.69 ± 0.23) | (−0.95 ± 0.35) |
| −3.44 ± 0.34 | −0.91 ± 0.28 | |||
| ACh | −5.77 ± 0.08 | 0.67 ± 0.07 | ||
| DMPP | −5.72 ± 0.19 | 0.84 ± 0.26 | ||
| Carbamylcholine | −4.78 ± 0.07 | 1.18 ± 0.19 | ||
| Acetylthiocholine | −4.00 ± 0.06 | 1.25 ± 0.16 | ||
| Choline | <−3 | |||
| Mecamylamine | −6.33 ± 0.05 | −1.17 ± 0.15 | ||
| DHβE | −5.82 ± 0.05 | −1.36 ± 0.19 | ||
| MLA | −5.18 ± 0.05 | −1.28 ± 0.15 | ||
| Hexamethonium | −4.97 ± 0.07 | −1.42 ± 0.25 | ||
| Lobeline | −4.68 ± 0.07 | −1.18 ± 0.20 | ||
| Alcuronium | −4.59 ± 0.05 | −1.26 ± 0.13 | ||
| Vecuronium | −4.56 ± 0.03 | −1.51 ± 0.15 | ||
| d-Tubocurarine | −4.21 ± 0.07 | −1.19 ± 0.19 | ||
| Pancuronium | −4.04 ± 0.08 | −1.04 ± 0.18 | ||
| Eserine | −3.89 ± 0.05 | −1.34 ± 0.19 | ||
| Decamethonium | −3.52 ± 0.07 | −1.24 ± 0.16 | ||
| Succinylcholine | ≪−3 |