Figure 6.

NADA does not modulate adenylyl cyclase activity in CHO‐hCB₁ cells. Adenylyl cyclase activity was determined using a membrane potential assay, as outlined in the Methods. (A) A concentration‐response relationship for FSK hyperpolarization of CHO‐hCB1 cells. FSK‐hyperpolarized cells with a pEC₅₀ of 6.7. Data were fit with a four‐parameter logistic equation, and each point represents the mean ± SEM of four independent experiments performed in duplicate. (B) A representative experiment showing raw fluorescence traces (RFU) of FSK‐induced hyperpolarization of CHO‐hCB₁ cells, and its reversal by CP55940. Drugs were added for the duration of the bar. (C) Normalized traces from a representative experiment (of 12) showing the lack of effect of NADA (30 μM) on the FSK‐induced hyperpolarization. The solvent blank trace has been subtracted from this data. (D) A bar chart summarizing the inhibitory activity of CP55940 (30 nM) on FSK‐stimulated hyperpolarization of CHO‐hCB₁ cells, in control conditions and after overnight treatment of cells with 200 ng⋅mL⁻¹ pertussis toxin (PTX). The bars represent the mean ± SEM of five or six independent experiments, each performed in duplicate or quadruplicate.