| Objective: To investigate the effects of Angiotensin-(1-7) on theexpression of insulin-degrading enzyme in hippocampus and cognitivefunction in diabetic rats.Methods:40SD male rats were divided into normal group, DMgroup, DM+Ang-（1-7） group, DM+Ang-（1-7）+A-779grouprandomly.Diabetes was induced by a single peritoneal injection ofstreptozotocin.Escape letency and frequncey of entrance into the target zonewere measured by the Morris water maze. The mRNA and protein level ofinsulin-degrading enzyme were examined with RT-PCR and Westernblot.Result: Comparing to the normal group, in DM group and DM+Ang-（1-7）+A-779group, escape letency were increasedsignificantly(P<0.05)and frequncey of entrance into the target zone weredecreased transparently（P<0.05）,the mRNA and protein level of IDE inhippocampal decreased significantly(P<0.05), Comparing to the DM group, the scores of escape letency and frequncey of entrance into the target zoneare highly improved in the DM+Ang-（1-7）group（P<0.05）, the mRNAand protein expression of IDE in hippocampal increased markedly(P<0.05).Conclusion:①The diabetic rats showed cognitive dysfunction whenthey were11weeks old, Ang-（1-7） could improve cognitive ability indiabetic rats.②The mRNA and protein level of IDE in hippocampal decreasedsignificantly, Ang-（1-7）could improve the mRNA and protein level of IDE.③Ang-（1-7） could improve cognitive ability in diabetic rats byincreased the mRNA and protein expression of IDE. Objective: To investigate the effects of Angiotensin-(1-7) on theexpression of β-amyloid protein in hippocampus and cognitive function indiabetic rats.Methods:40SD male rats were divided into normal group, DM group,DM+Ang（-1-7）group, DM+Ang（-1-7）+A-779group randomly.Diabeteswas induced by a single peritoneal injection of streptozotocin.Escape letencyand frequncey of entrance into the target zone were measured by the Morriswater maze. The expression of β-amyloid protein in hippocampus wasexamined by ELISA.Result: Comparing to the normal group, in DM group and DM+Ang-（1-7）+A-779group,escape letency were increasedsignificantly(P<0.05)and frequncey of entrance into the target zone weredecreased transparently（P<0.05）, the expression of Aβ in hippocampalwere increased significantly(P<0.05);Comparing to the DM group, thescores of escape letency and frequncey of entrance into the target zone arehighly improved in the DM+Ang-（1-7）group（P<0.05）, and the changesof Aβ significantly reduced(P<0.05).Conclusion:①the expression of Aβ in hippocampal were increased significantly, accompany cognitive dysfunction in diabetic rats,Itdemonstrated that neuronal dysfunction is involved in the progression ofdiabetic encephalopathy.②Ang-（1-7） could improve cognitive ability in diabetic rats byaccelerate hippocampus neuronal degrading of Aβ. |
