dFBr induced effects on response kinetics for agonists and partial agonists
The data were obtained by using nonlinear curve fitting algorithms from the dose–response curves shown in Fig. 2. Because individual responses were normalized to the response elicited by 1 mM ACh alone, the Imax value shown represents the maximum current elicited relative to that obtained with 1 mM ACh in the absence of dFBr. Values in brackets indicate the fractional change in the value resulting from coapplication of 1 μM dFBr. The statistical significance of observed differences in pEC50, Imax, and nH as a result of 1 μM dFBr coapplication was evaluated by using a paired Student's t test. P values are given in parentheses under the fold change. Values were considered statistically different at p ≤ 0.0001.
| Ligand | pEC50 ± S.E.M. [EC50 (μM)] | Imax ± S.E.M. | nH ± S.E.M. | |||
|---|---|---|---|---|---|---|
| 0 μM dFBr | 1 μM dFBr [Fold Change] | 0 μM dFBr | 1 μM dFBr [Fold Change] | 0 μM dFBr | 1 μM dFBr [Fold Change] | |
| ACh | 4.7 ± 0.1 (21) | 4.8 ± 0.3 (15) [1.0] (P = 0.58) | 1.3 ± 0.10 | 3.3 ± 0.6 [2.7] (P < 0.0001) | 1.4 ± 0.5 | 0.6 ± 0.2 [0.43] (P = 0.21) |
| Nicotine | 5.7 ± 0.3 (2.1) | 4.9 ± 0.5 (14) [0.9] (P = 0.15) | 0.38 ± 0.05 | 2.9 ± 1.0 [7.6] (P = 0.0069) | 1.1 ± 0.8 | 0.5 ± 0.4 [0.45] (P = 0.55) |
| Choline | N.D.* | 3.7 ± 0.1 (220) (P = N.D.) | 0.015 ± 0.003 | 0.14 ± 0.008 [9.3] (P < 0.0001) | N.D* | 1.7 ± 0.5 (P = N.D.) |
| Cytisine | 5.3 ± 0.5 (4.6) | 5.4 ± 0.3 (4.0) [1.0] (P = 0.91) | 0.053 ± 0.01 | 0.53 ± 0.06 [9.9] (P < 0.0001) | 0.94 ± 0.98 | 1.0 ± 0.6 [1.1] (P = 0.95) |
N.D., not determined.
↵* Value could not be accurately determined because of low efficacy of choline.