The antinociceptive potency of N-arachidonoyl-dopamine (NADA) and its interaction with endomorphin-1 at the spinal level

► We compared the spinal effects of N-arachidonoyl-dopamine (NADA) with endomorphin-1. ► NADA had lower potency than endomorhin-1. ► The antinociceptive effect NADA is due to spinal TRPV1 and CB1 receptors. ► The interaction of NADA and endomorphin-1 was additive.