Table 2

Correlation of −log EC₅₀ values for the facilitation of [³H]ACh outflow in the rat urinary bladder with constants for cloned (m) and native (M) muscarinic receptors

Correlation coefficient (r)			Slope		Constant	Reference
m₁	m₂	m₃	m₄	m₅		m₁	m₂	m₃	m₄	m₅
												Hulmeet al. (1990)
0.799	0.470	0.750	0.996^c	0.934^b		1.165	0.706	1.180	1.019^c	1.267^b	pK _i, pK _B	Caulfield et al. (1993)
					pIC₅₀	Maggioet al. (1994)
M₁	M₂	M₃	M₄			M₁	M₂	M₃	M₄
												Michael et al. (1989)
												Waelbroeck et al. (1990)
0.796	0.578	0.781	0.979^c			0.897	0.849	1.231	1.005^c		pK _i, pK _D	Doods et al. (1993)
												Melchiorre et al. (1995)
												Dörjeet al. (1990)
												Hulme et al. (1990)
0.732	0.448	0.849	0.887^2-a			0.838	0.654	1.166	0.889^2-a		pA ₂	Caulfieldet al. (1993)
												Lambrecht et al. (1995)
												Eglen et al. (1996)

The −log EC₅₀ values of six selective muscarinic receptor antagonists (4-DAMP, HHSiD, pirenzepine, AF-DX 116, methoctramine and tripitramine) were taken from table 1. Average constants related to the same antagonists at native and cloned muscarinic receptors were obtained from binding and functional experiments from the aforementioned references.
↵2-a P < .05, ^b P < .01, ^c P < .001.