Comparison of binding affinities of Sazetidine-A, nicotine, and DHβE at nAChR subtypes
Binding was measured using 100 pM [3H]EB as described under Materials and Methods. Values are the mean ± S.E.M. of three to five independent experiments. The Ki values of nicotine and DHβE at rat nAChRs were published previously (Xiao and Kellar, 2004) and are shown here for comparison. Approximately 90% of the nAChRs in rat forebrain are the α4β2 subtype.
Ligand | Ki | Selectivity (Ki ratio: rat α3β4/rat α4β2) | ||||||
|---|---|---|---|---|---|---|---|---|
| α4β2 (rat) | α4β2 (human) | Forebrain (rat) | α3β4 (rat) | |||||
| nM | ||||||||
| Sazetidine-A | 0.41 ± 0.16 | 0.64 ± 0.32 | 0.94 ± 0.48 | 10,000 ± 3000 | 24,000 | |||
| (−)-Nicotine | 10 ± 2 | 8.2 ± 0.2 | 12 ± 2 | 440 ± 60 | 44 | |||
| DHβE | 600 ± 70 | 410 ± 30 | 130 ± 50 | 110,000 ± 10,000 | 180 | |||