Figure 7. Concentration-dependent effect of W-15 on 5-HT activity at 5-HT_2A, 5-HT_2B, and 5-HT_2C receptors.

5-HT–mediated calcium mobilization was determined in the absence and presence of increasing concentrations of W-15 using HEK293 cells stably expressing corresponding 5-HT₂ subtypes on FLIPR^TETRA. Normalized results (relative fluorescence unit in fold of basal, basal was set as 0%, and 5-HT E_max in the absence of W-15 was set as 100%) represented mean values ± SEM from 3 independent assays, each performed in triplicate, and were analyzed in Prism. Schild plot analysis (D) indicated W-15 is a competitive antagonist against 5-HT. The average pA₂ values are 7.20 (5-HT_2A), 5.38 (5-HT_2B), and 6.88 (5-HT_2C). Panels A–C represent oncentration response curves for W-15 with increasing concentrations of 5-HT at 5-HT2A (A), 5-HT2B (B), or 5-HT2C (C) receptors.