Potency and efficacy of agonists carbachol, oxotremorine, pilocarpine and xanomeline of intracellular calcium response.

Potency is expressed as pEC50 (negative logarithm of half-efficient concentration), maximum increase EMAX is expressed as ratio of emissions at 340 to 380 nm excitations and efficacy is expressed as per cent of carbachol EMAX (maximum increase) and as G protein apparent affinity constant KG. Parameters were obtained by fitting equation Eq. 1 to the data from individual experiments in Fig. 1 (xanomeline) and the Fig. S1 in File S1 (carbachol, pilocarpine and oxotremorine) and subsequently by Eq. 3 using expression data from Table 2. Including Hill coefficient (slope factor) in the Eq. 1 does not improve the fit. Data are means±S.E.M. from 3 independent experiments.