Table 3.

Effect of nicotine on activation, desensitization, and permanent inactivation of human nAChRs

Human nAChR subtypeEC50 for activationEC50 for desensitization (m)EC50 for permanent inactivation (m)Fraction of activity expected to remain after chronic application of 0.2 μm nicotine followed by washout (%)
30 min24 hr
α4β23  × 10−71.7  × 10−84.8  × 10−84010
α3β2β4α53  × 10−68.7  × 10−78  × 10−690–10070–100
α74  × 10−53  × 10−81  × 10−815–30 20
  • From Olale et al. (1997) and Olale, Kuryatov, and Lindstrom, unpublished observations.