Table 1

[³⁵S]GTPγS binding to CHO cell membranes that were preincubated 10 min in the absence or presence of agonists

Preincubation	Incubation	[³⁵S]GTPγS binding
		%
Buffer	Buffer	100 ± 6
Buffer	⁺ Carbamylcholine (1 mM)	139 ± 7
Carbamylcholine (1 mM)	Carbamylcholine (1 mM)	128 ± 8
Carbamylcholine (1 mM)	⁺ Atropine (10 μM)	97 ± 3

Four sets of membrane samples were preincubated for 10 min in the absence or presence of 1 mM carbamylcholine. [³⁵S]GTPγS binding (± SEM) was measured after a second 10-min incubation in the absence or presence of carbamylcholine or after addition of 10 μM atropine, as indicated. The results are expressed as percentage of [³⁵S]GTPγS binding in the absence of carbamylcholine. (Representative of two duplicate experiments.)