Abstract: AIM: To observe the effects of gastrodin on expression of Iba1 in spinal cord in rats with vincristine-induced neuropathic pain. METHODS: SD rats were divided into 5 groups with random block design : control group, model group, gastrodin group (30 mg/kg, 60 mg/kg,120 mg/kg). Vincristine (125 μg/kg, i.p.) was administered to rats on alternate days to establish chemotherapy-induced neuropathic pain model in rat, then treated with different dose of gastrodin. Pain threshold and expression of Iba1 was determined respectively.RESULTS:Compared with control group, the pain threshold decreased in model group (P<0.05 or P<0.01).Compared with model group, the pain threshold increased in gastrodin groups (30 mg/kg,60 mg/kg,120 mg/kg) (P<0.05 or P<0.01). Moreover, compared with control group, the expression of Iba1 increased in model group (P<0.01).Compared with model group, the expression of Iba1 decreased in gastrodin groups (60 mg/kg,120 mg/kg) (P<0.05 or P<0.01).CONCLUSION: Gastrodin can relieve the chemotherapy-induced neuropathic pain, probably by inhibiting the activation of spinal dorsal horn microglia.

Key words: gastrodin, chemotherapy-induced neuropathic pain, vincristine, microglia