CRIP1a or CRIP1b did not significantly alter the maximum binding (Bmax) or [3H]SR141716 binding affinity (Kd) for CB1 in HEK 293 or CHO cells Membranes were prepared from HEK cells stably expressing CB1 receptors with or without CRIP1a or from CHO cells that were transiently transfected with CB1 receptor cDNA and an empty vector, CRIP1a or CRIP1b. Membranes were incubated with varying concentration of [3H]SR141716 as described under Materials and Methods. Data are mean Bmax and KD values ± S.E. from nonlinear regression analysis of the saturation binding curves. Statistical significance of differences in Bmax or KD values between HEK cells stably expressing CB1 or CB1 + CRIP1a was determined by the two-tailed non-paired t test; statistical differences among these parameters in the three transiently transfected CHO cell preparations were determined by analysis of variance with post hoc Bonferroni-adjusted t test or Dunnett's test. None of these inferential statistical tests revealed any significant differences in Bmax or KD values between these data sets.



pmol/mg protein nM
CB1 stable HEK 293 4 1.87 ± 0.26 1.05 ± 0.19
CB1 + CRIP1a stable HEK 293 4 2.01 ± 0.26 1.52 ± 0.20
CB1 transfected CHO 7 1.82 ± 0.34 0.75 ± 0.10
CB1 + CRIP1a transfected CHO 7 1.85 ± 0.35 0.80 ± 0.20
CB1 + CRIP1b transfected CHO
1.74 ± 0.40
1.64 ± 0.47