Studies on the apoptosis of autonomic neuron in streptozotocin-induced diabetic rats

Objective: The aim of the study was to investigate apoptosis of the autonomic neuron in streptozotocin-induced diabetic rats, and observe the effect of intervention with nerve growth factor(NGF) on the apoptosis. Methods: A total of 29 male Sprague-Dawley rats were divided into three groups, i.e. normal control(NC, n = 12), untreated diabetic(DM, n = 9) and diabetic treated with NGF daily of 500 μg/kg for 30 days(DM+NGF, n = 8). The diabetic rat models were produced by intraperitoneal injection with streptozotocin(65 mg/kg). Over 3 months since the diabetes were setup, the superior cervical sympathetic ganglions(SCG) and the celiac ganglions(CG) were removed and fixed with 10% paraformaldchyde. Apoptosis was measured using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling(TUNEL). Apoptotic index (AI) was calculated by computer image analysis system. Results: The AI of SCG and CG in DM and DM+NGF group were significant higher than those of NC group(P < 0.001) respectively. There was no difference of AI of SCG and CG between DM group and DM+NGF group (both P > 0.05). Conclusion: Neuron apoptosis may contribute to the pathophysiology of diabetic autonomic neuropathy and NGF can not prevent the apoptosis of autonomic neuron in diabetic rats.