Involvement of G
proteins/AC/cAMP/PKA pathway in DEX-induced inhibition of Na
1.8 currents. (A-C) Loading neurons with 1 mM GDPβ-s or PTX completely abolished the inhibitory effect of DEX on Nav1.8 currents. *p < 0.05. (D, E) Pre-incubation PKA inhibitor Rp-cAMP (50 μM) inhibited Nav1.8 currents. Co-application of DEX did not cause a further reduction of the current amplitudes. *p < 0.05. (F, G) Pre-incubation cAMP analogues 8-Br-cAMP (500 μM) prevented DEX-induced inhibition of Nav1.8 currents. (H, I) Pre-incubation AC activator forskolin (0.1 μM) prevented DEX-induced inhibition of Nav1.8 currents.