Table 4.

Pharmacological parameters of the concentration–response curves of [³⁵S]GTPγS binding stimulation induced by N-propylapomorphine (NPA) in human caudate of subjects with schizophrenia and controls

	log EC50H	log EC50L	Emax (%)	Fraction H (%)
Schizophrenia (n = 17)	− 8.11 ± 0.40	− 5.17 ± 0.49	22 ± 2	56 ± 10
Control (n = 17)	− 8.14 ± 0.37	− 4.82 ± 0.36	23 ± 2	49 ± 8

Values are means ± SE of independent experiments performed in tissue homogenates from 17 subjects in each group. logEC₅₀ values are log normalized values of the agonist concentration that elicited half-maximal effect obtained from concentration–response curves. E_max is the maximal % stimulation of [³⁵S]GTPγS binding over basal values. H and L represents the high-, and low-affinity fractions of the curves, respectively