EC50 values and maximal efflux rates for DHβE-sensitive and DHβE-resistant 86Rb+ efflux
| Agonist | DHβE-Sensitive Response | DHβE-Resistant Response | ||
|---|---|---|---|---|
| EC50 | Emax | EC50 | Emax | |
| μM | % | μM | % | |
| A85380 | 0.018 ± .006 | 0.120 ± .006 | 40.0 ± 8.5 | 0.392 ± .020 |
| ABT418 | 12.6 ± 3.4 | 0.153 ± .010 | 277 ± 150 | 0.134 ± .020 |
| Acetylcholine | 7.18 ± .29 | 0.149 ± .011 | 550 ± 61 | 0.158 ± .005 |
| Anabasine | 52.9 ± 23.9 | 0.035 ± .004 | No Response | No Response |
| Anatoxin-a | 0.96 ± .26 | 0.070 ± .004 | 23.8 ± 4.5 | 0.084 ± .004 |
| Carbachol | 150 ± 40 | 0.188 ± .013 | 2600 ± 830 | 0.109 ± .010 |
| Cytisine | 0.013 ± .011 | 0.017 ± .003 | 150 ± 60 | 0.068 ± .007 |
| DMPP | 6.1 ± 1.4 | 0.102 ± .005 | 160 ± 110 | 0.043 ± .008 |
| (±)-Epibatidine | 0.057 ± .016 | 0.289 ± .019 | 2.2 ± 0.3 | 0.392 ± .017 |
| (+)-Epibatidine | 0.093 ± .029 | 0.211 ± .015 | 3.8 ± 0.9 | 0.410 ± .024 |
| (−)-Epibatidine | 0.049 ± .008 | 0.223 ± .007 | 3.7 ± 1.1 | 0.498 ± .034 |
| Epiboxidine | 0.23 ± .04 | 0.125 ± .004 | 32.3 ± 6.2 | 0.236 ± .013 |
| Methylcarbachol | 19.4 ± 5.4 | 0.192 ± .012 | 730 ± 80 | 0.218 ± .007 |
| (−)-Nicotine | 1.39 ± .42 | 0.112 ± .007 | 130 ± 20 | 0.164 ± .007 |
| (+)-Nicotine | 13.4 ± 8.6 | 0.047 ± .006 | 1200 ± 330 | 0.035 ± .012 |
| Nornicotine | 17.7 ± 13.1 | 0.050 ± .013 | 190 ± 190 | 0.034 ± .009 |
| TMA | 185 ± 32 | 0.203 ± .009 | 890 ± 720 | 0.040 ± .007 |
Kinetic values for the activation of both DHβE-sensitive and DHβE-resistant 86Rb+ efflux from mouse forebrain synaptosomes were calculated by nonlinear least squares curve fitting of the results shown in Fig. 5 using the Michaelis-Menten equation. Values given are mean ± S.E.M. of the estimates obtained for results of at least three separate experiments. E maxvalues are the percentage of total synaptosomal 86Rb+stimulated by agonist exposure.