Table 1

Parameters describing effects of nicotine exposure on nAChR numbers and function

Cell type and nAChR subtypeMeasureτParameterEC50/IC50
hr % increase/(decrease) μM
TE671/RDintracellular Carb-sensitive I-Bgt binding0.69 /2685 /340
(alpha-1beta-1 gamma delta)intracellular Carb-insensitive I-Bgt binding0.69 /2611 /46
Cell surface Carb-sensitive I-Bgt binding0.035 /6.9/14(50) /50/140
Cell surface Carb-insensitive I-Bgt binding0.035 /0.34/23(60) /60/50
Membrane [3H]ACh binding0.36 /2660 /360
140 /2901.3 /800
Membrane Carb-sensitive I-Bgt binding0.36 /2640 /340
88 /4401.3 /800
Membrane Carb-insensitive I-Bgt binding0.36 /260 /38
Function0.016 /0.32(45) /(55)
SH-SY5YMembrane [3H]ACh binding23580
(alpha-3 beta-4)270 /7706 /480
Function0.0027 /0.12(56) /(26)
SH-SY5YIntracellular I-Bgt binding0.14 /3623 /240
(alpha-7)Cell surface I-Bgt binding1.1 /90(34) /100
Membrane I-Bgt binding180810
BC3H-1Membrane I-Bgt binding6.980
(alpha-1 beta-1 gamma delta)93200

The indicated cell types expressing specified nAChR subtypes were subjected to nicotine treatments and measures of radioligand binding densities or functional activity as described in “Experimental Procedures.” Summarized here (to two significant digits) are time constants for nicotine effects (hr), the percentage change in nAChR numbers or function reflecting these effects (decreases are enclosed in parentheses) and the EC50 (or IC50 in parentheses) values for those effects (μM). In cases where effects were bi- or tri-phasic, parameters in each column are separated in order by “slashes.” See appropriate figure legends and text for details.