Intracerebroventricular administrations of angiotensin IV (Ang IV) ameliorate cognitive disorder in diabetic rats
- Author:
Hui-Min Du
;
-Lin Niu MM
;
Ke-Xiang Zhao
;
Juan Li MMS
;
Qian Xiao
- Publication Type:Journal Article
- From:Neurology Asia
2013;18(2):195-202
- CountryMalaysia
- Language:English
-
Abstract:
Cognitive impairment is a common complication of diabetes. Hippocampus plays an important role
in cognitive function. In hyperglycemia, synaptophysin, a crucial synaptic vesicle membrane protein
in hippocampus neuron is found to be down-regulated. Recent evidences have shown that angiotensin
IV can facilitate memory acquisition and recovery. However, whether it can also improve cognitive
functions of diabetic rats with cognitive disorder, and the possible mechanisms are uncertain. Hence,
the objectives of this study. Forty fi ve Sprague Dawley male rats were randomly divided into three
groups: Control, diabetic group and diabetes with angiotensin IV treatment group. The cognitive
functions, mainly learning and memory of the rats were evaluated using Morris water maze task. The
synapses ultrastructure, relative mRNA concentrations and protein expression levels of synaptophysin
in hippocampus CA1 area were estimated using transmission electron microscope, RT-PCR,
immunohistochemistry and western blotting, respectively. Our study showed that in the diabetic rats with
angiotensin IV treatment, the cognitive impairment as measured by Morris water maze task improved,
the ultrastructure of synapses in hippocampus reversed, the relative mRNA concentrations and protein
levels of synaptophysin in hippocampus signifi cantly increased, when compared with diabetic rats.
We conclude that angiotensin IV plays an important role in improving cognitive function of diabetic
rats. The possible mechanisms are up-regulating the expression of synaptophysin and normalizing the
ultrastructure of synapses in hippocampus.
- Full text:P020150706524508145886.pdf
