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Relationship Between The LRP-1 Expression In Hippocampal Microvessels And The Cognitive Function Impairment

Posted on:2005-07-03Degree:DoctorType:Dissertation
Country:ChinaCandidate:J H GuoFull Text:PDF
GTID:1104360122492017Subject:Neurology
Abstract/Summary:PDF Full Text Request
OBJECTIVE (1)to investigate the LRP-1 expression in frontal lobe, hippocampus and striatum in different month-old rats, and the correlation between the LRP-1 density of hippocampal CAl microvessels and the cognitive function impairment in aging and the processes of chronic reduction of cerebral blood flow. METHODS (1)Including five groups: Five one-month-old rats, eleven three-month-old rats, eleven ten-month-old rats and eight twenty-four-month-old rats, six operated rats and six sham-operated rats. (2)Using FACS to test and calculate the mean fluorescent index of LRP-1 in frontal lobe, hippocampus and striatum in different month-old rats. (3)Using immunohistochemical techniques to test the expression of LRP-1 in the nerve cells and microvessels of hippocampal CAl, and detected VI factor related antigen and GFAP expression density in hippocampal CAl with aging. (4)Using Marris water maze to estimate the cognitive function, (5)three-month-old rats were subjected to permanent occlusion of both common carotid arteries. (6)Radiation and immunology techniques were used to test the concentration of amyloid beta-peptide in cerebral spinal fluid. RESULTS (1)The mean fluorescent index of LRP-1 of ten-month old rats was significantly reduced in hippocampus, and increased in striatum, But there were no significant difference between every two groups in frontal lobe. The mean fluorescent index of LRP-1 in hippocampus was significantly higher than that in frontal lobe and striatum of one-month-old and three-month-old group. (2)Hippocampal CAl nerve cells and microvessels all had LRP-1expression by imraunohistochemical techniques. The density of microvessvels was higher than that of nerve cells in different groups. With aging, the expression density of LRP-1 in hippocampal CA1 microvessels was decreasing quickly. But in nerve cells, only significantly decreased in twenty-four-month-old group. (3) The distance for twenty-four-month-old rats to locate the hidden platform was significant longer than three-month old and ten-month old rats. The decreased density of LRP-1 in the microvessels of the twenty-four-month-old rats correlated with the cognitive function impairment. The density of LRP-1 in the nerve cells and VIII factor related antigen was also significant decreased in twenty-four-month old rats, but had not a relationship with the cognitive function impairment. (4)0ne month after vascular occlusion, the occluded animals displayed an significantly impaired performance throughout the training period. Six months after surgery, the operated rats showed decreased LRP-1 density in hippocampal CA1 microvessels and increased GFAP density. But VIII factor related antigen density had no significant differences between the operated rats and the sham-operated rats. The LRP-1 density in hippocampal CA1 microvessels correlated with the Marris water maze performance. (5)The concentration of amyloid beta-peptide in cerebral spinal fluid significantly decreased in the operated rats. CONCLUSION (1)With aging, the LRP-1 expression in hippocampus was decreasing quickly, especially in the hippocampal CA1 microvessels ㏕here were highly correlation between the LRP-1 expression density in microvessels ofhippocampal CA1 and the cognitive function impairment in aging rats. (3)With the chronic reduction of cerebral blood flow in the adult rat, the LRP-1 density in hippocampal CA1 microvessels correlates with the cognitive function impairment.
Keywords/Search Tags:LRP-1, Aging, Microvessels, Cognitive function
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