Antihyperalgesic, but not antiallodynic, effect of melatonin in nerve-injured neuropathic mice: Possible involvements of the l-arginine–NO pathway and opioid system

Untitled

“…43 These results suggest that although MLT has different effects on neuropathic pain-related behaviors, the L-arginine-NO pathway and opioidergic system are involved in its anti-hyperalgesic effect in nerve-injured mice. 43 …”

“…43 One to 5 weeks after the surgery, marked mechanical allodynia and thermal hyperalgesia developed in the neuropathic mice, but MLT at higher doses blocked the thermal hyperalgesia but not the mechanical allodynia. 43 Administration of both L-arginine and naloxone, at doses that produced no effect on their own, partially reversed the anti-hyperalgesic effect of MLT. 43 These results suggest that although MLT has different effects on neuropathic pain-related behaviors, the L-arginine-NO pathway and opioidergic system are involved in its anti-hyperalgesic effect in nerve-injured mice.…”

“…43 Administration of both L-arginine and naloxone, at doses that produced no effect on their own, partially reversed the anti-hyperalgesic effect of MLT. 43 These results suggest that although MLT has different effects on neuropathic pain-related behaviors, the L-arginine-NO pathway and opioidergic system are involved in its anti-hyperalgesic effect in nerve-injured mice. 43 …”

“…MLT on mechanical allodynia and thermal hyperalgesia in mice with partial tight ligation of the sciatic nerve, and the influence of the NO precursor L-arginine and the opiate antagonist naloxone on those effects. 43 A plantar analgesic meter was used to assess thermal hyperalgesia, and nerve injury-induced mechanical hyperalgesia was assessed with von Frey filaments. 43 One to 5 weeks after the surgery, marked mechanical allodynia and thermal hyperalgesia developed in the neuropathic mice, but MLT at higher doses blocked the thermal hyperalgesia but not the mechanical allodynia.…”

“…43 A plantar analgesic meter was used to assess thermal hyperalgesia, and nerve injury-induced mechanical hyperalgesia was assessed with von Frey filaments. 43 One to 5 weeks after the surgery, marked mechanical allodynia and thermal hyperalgesia developed in the neuropathic mice, but MLT at higher doses blocked the thermal hyperalgesia but not the mechanical allodynia. 43 Administration of both L-arginine and naloxone, at doses that produced no effect on their own, partially reversed the anti-hyperalgesic effect of MLT.…”