Antinociceptive effect of l-arginine in diabetic mice

Abstract

The antinociceptive effect of L-arginine in streptozotocin-indueced diabetic mice was examined. Although s.c. administration of l-arginine produced a dose-dependent inhibition of the tail-flick response in both non-diabetic and diabetic mice, the antinociceptive response was greater in diabetic mice than in non-diabetic mice. The antinociceptive effects of l-arginine in both diabetic and non-diabetic mice were significantly antagonized by s.c. administration of naltrindole, a selective δ-opioid receptor antagonist. However, neither β-funaltrexamine, a selective μ-opioid receptor antagonist, nor nor-binaltorphimin, a selective κ-opioid receptor antagonist, significantly affected the antinociceptive effect of l-arginine in diabetic and non-diabetic mice. These results suggest that l-arginine produces a marked antinociceptive effect in diabetic mice through the activation of δ-opioid receptors.