Figure 3.

NADA activates peripheral VR1. (a) Effect of increasing concentrations of NADA and anandamide on intracellular Ca²⁺ in neonatal DRG neurons. *, P < 0.05 vs. NADA (t test). (b) Inhibition by VR1 antagonists of NADA (1 μM) or capsaicin (1 μM) enhancement of intracellular Ca²⁺ in isolated DRG neurons. *, P < 0.05 vs. vehicle (t test). (c) Effect of increasing concentrations of NADA and anandamide on the release of CGRP-LI and SP-LI from rat dorsal spinal cord slices. (d) Effect of capsaicin pretreatment, VR1 antagonism, and incubation in a Ca²⁺-free medium on the effect of NADA on CGRP-LI and SP-LI. *, P < 0.05 vs. vehicle (t test). ND, not detectable.