Effect of arvanil (N-arachidonoyl-vanillyl-amine), a nonpungent anandamide-capsaicin hybrid, on ion currents in NG108-15 neuronal cells

The effects of arvanil (N-arachidonoyl-vanillyl-amine), a structural hybrid between capsaicin and anandamide, on ion currents in a mouse neuroblastoma and rat glioma hybrid cell line, NG108-15, were examined with the aid of the whole-cell voltage-clamp technique. Arvanil (0.2-50μM) caused an inhibition of voltage-dependent L-type Ca²⁺ current (I_Ca,L) in a concentration-dependent manner. Arvanil produced no change in the overall shape of the current-voltage relationship of I_Ca,L. The IC₅₀ value of arvanil-induced inhibition of I_Ca,L was 2μM. Arvanil (5μM) could shift the steady-state inactivation curve of I_Ca,L to a more negative potential by approximately -15mV. No effect of arvanil (20μM) on delayed rectifier K⁺ current (I_K(DR)) was observed; however, capsaicin (20μM), glyceryl nonivamide (20μM) and capsinolol (20μM) suppressed it significantly. Arvanil (20μM) caused a slight reduction in the amplitude of erg (ether-à-go-go-related)-mediated K⁺ current (I_K(erg)) without modifying the activation curve of this current, while capsaicin and glyceryl nonivamide were more effective in suppressing I_K(erg). Under current-clamp configuration, arvanil decreased the firing frequency of action potentials. Arvanil-mediated inhibition of I_Ca,L appeared to be independent of its binding to either vanilloid or cannabinoid receptors. The channel-blocking properties of arvanil may, at least in part, contribute to the underlying mechanisms by which it affects neuronal or neuroendocrine function.