title: [Effects of angiotensin-(1-7) on hippocampal expressions of GFAP and GDNF and cognitive function in rats with diabetes mellitus].
abstract: OBJECTIVE
  To explore the effects of angiotensin-(1-7) on the learning and memory abilities and the expressions of glial fibrillary acidic protein (GFAP) and glial cell line-derived neurotrophic factor (GDNF) in the hippocampus of diabetic rats.
  
  
  METHODS
  Forty male SD rats were randomly assigned into 4 groups, namely the control group, diabetic group, Ang(1-7)-treated diabetic group (DM1 group), and Ang-(1-7)- and Mas receptor antagonist A779-treated diabetic group (DM2 group). Diabetic rat models were established by a single intraperitoneal injection of streptozotocin (60 mg/kg). The cognitive function of the rats was assessed with Morris water maze (MWM) test. The expressions of GDNF in the hippocampus were examined by RT-PCR and Western blot. Nissl staining was performed to evaluate the morphological changes in rat hippocampus. The expressions of glial fibrillary acidic protein (GFAP, a key indicator of astrocytic reactivity) and caspase-3 were measured by immunohistochemistry.
  
  
  RESULTS
  Compared with the control group, the diabetic rats exhibited significantly impaired learning and memory abilities (P<0.05) with lowered expression of GDNF and increased caspase-3 expression in the hippocampus (P<0.05) and significant hippocampal neuronal and astrocyte injuries (P<0.05). Treatment with Ang(1-7) obviously improved the learning and memory abilities of the diabetic rats (P<0.05), increased GDNF and GFAP expressions (P<0.05), lowered caspase-3 expression (P<0.05), and increased the number of surviving neurons in the hippocampus (P<0.05). Such effects of Ang(1-7) effect was blocked by treatment with A779 of the diabetic rats.
  
  
  CONCLUSIONS
  Ang(1-7) can alleviate cognitive dysfunction in diabetic rats possibly by up-regulating the expressions of GFAP and GDNF and promoting neuron survival in the hippocampus.
authors.affiliation: Endocrinology Group, Department of Geriatrics, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.E-mail: zhangdongling28@163.com.
authors.forename: Dongling
authors.initials: D
authors.lastname: Zhang
authors.forename: Qian
authors.initials: Q
authors.lastname: Xiao
authors.forename: Huiqiong
authors.initials: H
authors.lastname: Luo
authors.forename: Kexiang
authors.initials: K
authors.lastname: Zhao
mesh_terms: D000803:Angiotensin I / Q000494:pharmacology*; D000818:Animals; D001253:Astrocytes; D053148:Caspase 3 / Q000378:metabolism; D003071:Cognition; D003072:Cognition Disorders; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008568:Memory; D009474:Neurons; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin
chemical_list: C495041:Gdnf protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D005904:Glial Fibrillary Acidic Protein; D010446:Peptide Fragments; D013311:Streptozocin; D000803:Angiotensin I; C505410:Casp3 protein, rat; D053148:Caspase 3; C118790:angiotensin I (1-7)