Figure 1.

Saturation curves for the specific binding of [³H]-DAMGO on cell membranes of PAG, vPAG, mTH, vTH and spinal cord prepared from sham-operated and FBC model mice. Tissue samples were collected 14 days after the sham operation (Sham) or tumour implantation (tumour-implanted), and membranes prepared from the PAG (A), vPAG (B), mTH (C), vTH (D) and spinal cord (E) were used for the binding assay. [³H]-DAMGO binding was examined using concentrations from 0.5 to 16 nM. Specific binding was defined as the difference in binding observed in the absence and presence of 10 μM unlabelled DAMGO. Each value represents the mean ± SD of two independent experiments (eight mice per sample in each experiment). The K_d and B_max of [³H]-DAMGO in those regions are shown in (F). The values were determined from the saturation curves and Scatchard plots analysis, and at least six concentrations were used for each analysis. ***P < 0.001 versus sham group (two-way ANOVA, Dunnett's multiple comparison test).