TABLE 1

EC50 values and Rmax values for α-CtxMII-sensitive and -resistant agonist-stimulated dopamine release

EC50RmaxnH
μM units
α-CtxMII-resistant
A85380 0.0038 ± 0.0001 8.19 ± 0.11 1.13 ± 0.05
Acetylcholine 1.02 ± 0.06 9.45 ± 0.31 0.91 ± 0.07
Cytisine 0.47 ± 0.09 3.10 ± 0.55 0.41 ± 0.08
(±)-Epibatidine 0.012 ± 0.001 13.18 ± 1.08 0.75 ± 0.12
l-Nicotine 1.61 ± 0.19 8.48 ± 0.39 1.35 ± 0.26
α-CtxMII-sensitive
A85380 0.0013 ± 0.0001*** 3.55 ± 0.20 0.90 ± 0.12
Acetylcholine 0.15 ± 0.08*** 3.51 ± 0.59 0.86 ± 0.53
Cytisine 0.031 ± 0.011** 3.00 ± 0.21 1.01 ± 0.40
(±)-Epibatidine 0.00078 ± 0.00021*** 4.98 ± 0.52 0.76 ± 0.24
l-Nicotine 0.77 ± 0.27* 4.20 ± 0.65 0.63 ± 0.25
Rmax (Relative to ACh)
EC50 Ratios Resistant/Sensitive Resistant Sensitive
A85380 2.9 ± 0.2 0.87 ± 0.04 1.01 ± 0.18
Acetylcholine 6.8 ± 3.6 1.00 ± 0.05 1.00 ± 0.24
Cytisine 15.2 ± 6.1 0.33 ± 0.06 0.85 ± 0.16
(±)-Epibatidine 15.4 ± 4.3 1.39 ± 0.12 1.42 ± 0.28
L-Nicotine 2.1 ± 0.8 0.90 ± 0.05 1.20 ± 0.21

  • *, P < 0.05; **, P < 0.01; ***, P < 0.001 by t test comparing EC50 values for α-CtxMII-resistant and -sensitive agonist-stimulated dopamine release.