Table 5.

B_max and K_D values from [³H]CP55,940 saturation binding analysis in spinal cord of vehicle- and THC-treated wild-type and S426A/S430A CB₁ receptor knock-in mice

Ligand	WT mice		S426A/S430A mice
	Bmax (fmol/mg)	KD (nm)	Bmax (fmol/mg)	KD (nm)
Vehicle	426 ± 42	1.60 ± 0.29	406 ± 62	1.69 ± 0.33
Δ9-THC	231 ± 42*	0.78 ± 0.23	253 ± 60	0.73 ± 0.28

Data are mean B_max and K_D values ± SEM (n = 5–6). Spinal cord membranes from vehicle- and THC-treated WT and S426A/S430A CB₁ receptor knock-in mice were incubated with varying concentrations of [³H]CP55,940 with and without 5 μm unlabeled CP55,940 to measure nonspecific binding, as described in Materials and Methods. Saturation binding curves were fit by nonlinear regression.

*p < 0.05 different from vehicle-treated mice of the same genotype as determined by two-way ANOVA and planned comparison with Bonferroni post hoc test.