Effect of propentofylline on activation of astrocytes in spinal cord in a rat model of diabetic neuropathic pain

Abstract

Objective To investigate the effect of propentofylline on activation of astrecytes in the spinal cord in a rat model of diabetic neuropathic pain(DNP).Methods Pathogen-free SD rats of both sexes aged 2 months weighing 180-200 g were used in this study.Diabetes was induced by intraperitoneal(IP)1% streptozocin(STZ)60 mg/kg.Blood glucose level was measured before(T1)and at 2,7,14,21,28,35 days after IP STZ injection(T2-7).Diabetes Was confirmed by blood glucose level>16.7 mmol/L.Paw withdrawal threshold to von Frey filament stimulation(PWT)Was measured at T1,T3-7.Induction of neuropathic pain WaS considered successful in ccessful in animals with PWT reduced by more than 50%of the baseline.Twenty animals in which DNP was successfully induced were randomly divided into 2 groups(n=10 each):groupⅠdiabetes meatus(DM)and groupⅡ pmpentofylline(PP).Another 10 age-matched normal rats served as control group(Nc),Grorp PP received IP propentofylline 10 ms/kg once B day for 7 consecutive days starting from T6.The animals were killed at T2 and the lumbar segment of the spinal cord Was removed for determination of glial fibrillary acidic protein(GFAP)in the astmcytes in the spinal cord by immuno-histochemical assay.Results PWT Was aignitlcantly lower at T4-7 in group DM and PP than in control group(NC)and Was significantly higher at T7 in group PP than in group DM.Immuno-himochemical assay showed that GFAP-positive astrocytes in the dorsal hom of the spinal cord was significantly increased in diabetic rats and pmpentofyUine significantly attenuated the increase.Conclusion Inhibition of astwcytes in the spinal cord is involved.m attenuation of diabetic neuropathic pmn by propentofylline. Key words: lndoles; Diabetic neuropathy; Neuralgia; Spinal cord; Astwcytes