Abstract: The objectives were to investigate the role of the alteration of mitochondria transmembrane potentials in apoptosis in hippocampal neurons of STZ-DM rats and the possible effect of APP17 peptide on it. DM models were established by injection of streptozotocin intraperitoneal, the APP17 peptide treated group were injected with APP17 peptide three times a week, whereas the control and DM groups were given saline. Single cell of hippocampus was isolated, and mitochondria transmembrane potentials and the percentage of cell in apoptosis were measured by means of flow cytometry (FCM) at the 11th week when the animals were sacrificed. The neurons in hippocampus of DM group had lower mitochondria transmembrane potentials and higher apoptotic rate than those of the control group. APP-17 peptide could significantly blocked the mitochondria transmembrane potentials collapse and apoptosis. Decreased mitochondria transmembrane potential and related apoptosis may contribute to the mechanism of diabetic encephalopathy. APP-17 peptide palys an anti apoptosis role in it.

Key words: APP-17, peptide diabetic, encephalopathy, mitochondria transmembrane potential, apoptosis, hippocampus