TABLE 1

Parameters of [³⁵S]GTPγS binding to membranes from CHO cells

E_MAX is expressed as percentage of increase above basal binding, and concentrations of agonists producing EC₅₀ are expressed as negative logarithms of [³⁵S]GTPγS binding to membranes from CHO cells expressing M₁ or M₂ receptors, respectively. Data are means ± S.E.M. from four to six independent experiments performed in quadruplicates.

	M₁		M₂
	pEC₅₀	E_MAX	pEC₅₀	E_MAX
		% above basal		% above basal
Without preincubation
Xanomeline	8.04 ± 0.01^*	228 ± 9^*	N.E.	N.E.
Carbachol	6.08 ± 0.01	179 ± 7	6.12 ± 0.05	187 ± 0.06
+ 3 nM xanomeline	5.97 ± 0.03^*	179 ± 8	N.M.	N.M.
+ 10 nM xanomeline	5.79 ± 0.04^*	183 ± 7	6.01 ± 0.05	186 ± 0.06
+ 30 nM xanomeline	5.39 ± 0.01^*	184 ± 8	5.89 ± 0.03^*	185 ± 0.09
+ 100 nM xanomeline	5.02 ± 0.02^*	184 ± 9	5.63 ± 0.02^*	182 ± 0.08
+ 300 nM xanomeline	N.M.	N.M.	5.16 ± 0.05^*	196 ± 0.09
With 60-min preincubation
Xanomeline	8.15 ± 0.04^*	224 ± 6^*	7.78 ± 0.03	75 ± 5^*
Carbachol	6.08 ± 0.04	189 ± 6	6.12 ± 0.03	188 ± 6
+ 3 nM xanomeline	5.92 ± 0.04^*	189 ± 7	N.M.	N.M.
+ 10 nM xanomeline	5.68 ± 0.03^*	189 ± 8	6.02 ± 0.01	191 ± 7
+ 30 nM xanomeline	5.32 ± 0.03^*	195 ± 9	5.68 ± 0.02^*	197 ± 8
+ 100 nM xanomeline	4.91 ± 0.03^*	194 ± 11	5.28 ± 0.03^*	190 ± 8
+ 300 nM xanomeline	N.M.	N.M.	4.97 ± 0.04^*	194 ± 7
With 60-min preincubation followed by washing
Xanomeline	5.98 ± 0.03	208 ± 6^*	5.81 ± 0.03^*	62 ± 5^*
Carbachol	6.07 ± 0.03	186 ± 6	6.06 ± 0.03	195 ± 6
+ 0.3 μM xanomeline	6.08 ± 0.04	189 ± 7	6.04 ± 0.04	190 ± 8
+ 1 μM xanomeline	6.18 ± 0.01	187 ± 9	6.07 ± 0.05	181 ± 9
+ 3 μM xanomeline	5.84 ± 0.05^*	194 ± 8	6.01 ± 0.02	173 ± 7^*
+ 10 μM xanomeline	5.42 ± 0.05^*	178 ± 9	5.86 ± 0.01^*	165 ± 7^*

N.E., no effect; N.M., not measured.
↵* P < 0.05, significantly different from carbachol or carbachol alone by t test or ANOVA followed by Dunnett's test.