Evaluation of the Role of Brain-Derived Neurotrophic Factor in Programmed Cell Death in Hippocampus of Diabetic Rats

Diabetes mellitus results in wide disorders in central and peripheral nervous systems. Prevalence of cognitive disorders in diabetic patients is more compared to that in non-diabetic patients. Brain-derived neurotrophic factor (BDNF) prevents cell death by stimulating synthesis of antiapoptic factors in cell cultures. The present study aimed at investigating the effects of experimental diabetes on programmed cell death in hippocampus and its relation with the amount of BDNF and the related gene expression. Twenty male Wistar rats (200+20 g) were divided into two groups: control and diabetic. Diabetes was induced by injection of streptozotocin (single dose, 50mg/kg). Duration of the study was 8 weeks. At the end of the experiment, the rats were anesthetized by thiopental sodium and then brain was removed. Immediately, the hippocampus was removed on ice and kept frozen by liquid nitrogen and kept in freezer -800C until detection. Hippocampus tissue was homogenized in prepared buffer and after centrifugation supernatant was used for determination of apoptosis, level of BDNF protein and its gene expression. An increase in the amount of apoptosis following induction of diabetes was observed. Furthermore, diabetes induction increased the level of BDNF protein and its gene expression compared to the control group (P<0.05). Induction of diabetes increased the amount of apoptosis in the hippocampus of diabetic rats. As a defense mechanism, the level of BDNF protein and the related gene expression increases to prevent the apoptosis in the hippocampus.