TABLE 2

Interaction of S33138 and other antipsychotics at hD₃, hD_2L, and hD_2S receptors compared with sites underlying metabolic, cardiovascular, and autonomic side effects

All studies were performed in CHO cell lines. Drug affinities at hD₃, hD_2L, and hD_2S sites were determined as summarized in Table 1. Radioligands (concentrations) for the other sites were as follows: h5-HT_2C receptors ([³H]mesulergine, 0.3 nM); hα_1A-, hα_1B-, and hα_1C-ARs ([³H]prazosin, 0.3 nM); hH₁ receptors ([³H]pyrilamine, 2.0 nM); hM₁ receptors ([³H]pirenzepine, 2.0 nM); hM₂ receptors ([³H]AF-DX384, 2.0 nM); and hM₃ and hM₄ receptors ([³H]4-diphenylacetoxy-N-methylpiperidine, 0.2 nM). Data for S33138 at hα₁-AR subtypes and h5-HT_2C receptors are transformed from pK_i values in Table 1 and are included for the sake of completeness. Data are means ± S.E.M. based on three to four determinations, each performed in triplicate.