Figure 1.

Dose-response profiles for serotonin to enhance GTPγ³⁵S binding in the 5-HT_1D and 5-HT_1B receptors from the gorilla and the guinea-pig. GTPγ³⁵S binding was measured in the presence of serotonin at various concentrations in cell membranes expressing indicated receptors. Serotonin-dependent GTPγ³⁵S binding was plotted as a function of serotonin concentrations, and fitted to a binding isotherm for a single class of binding sites. The data represent mean values±standard errors from three experiments.