Change of TLR3 in Microglia in Spinal Cord of Rats with Diabetic Neuropathy

Objective:To observe change of Toll-like receptor(TLR3) in microglia in spinal cord of rats with diabetic neuropathy.Mail SD rats were divided into 2 groups(n=10,each):diabetes mellitus group(Group D) and control group(Group C).Methods:Diabetes mellitus was induced by intraperitoneal streptozotocin(STZ) 60 mg/kg and confirmed by blood glucose level 16.7 mmol/L.Control group was induced by intraperitoneal saline.The blood glucose level and the behavior score of rats were recorded.The expression of TLR3 was observed in microglia in spinal cord through immunofluorescence double staining and laser scanning confocal microscopy technique.Results:The blood glocose level in Group D was significantly increased after intraperitoneal STZ injection 2d as compared with Group C.The mechanical withdrawal threshold was significantly decreased after intraperitoneal STZ at 14-28d as compared with the baseline in Group D and was significantly lower than that in Group C.Immunofluorescence demonstrated that the expression of TLR3 in the dorsal horn was significantly up-regulated and mainly in microglia after STZ injection in Group D.Conclusions:TLR3 of microglia are possibly involved in the pathogenesis of diabetic neuropathic pain.