The mechanism of changes of postsynaptic dense substances in vascular dementia rats
HE Yu,JIN Yu-fen,ZHANG Yu (the Second Hospital of Jilin University, Changchun 130041, China)
Objective To investigate the relationship of altered expression of N-methyl-D-aspartic acid receptor 2B(NR2B) and ealcium/calmodulin-dependent protein kinase Ⅱ (CaMK Ⅱ) to development of vascular dementia in rats. Methods Ninety-six Wistar rats were randomly divided into sham-operated group, vascular dementia(VaD) model group and memantine-treated group. The vascular dementia rat model was established by permanent bilateral occlusion of the common carotid arteries. The changes of the expression of NR2B in hippocampus were measured by RT-PCR and the changes of the CaMK Ⅱ activities were determined by incorporation of r-~(32)P into histone. Results Compared with the sham rats, the level of NR2B in hippocampus increased significantly at 4 weeks after operation (P0.05)and decreased at 8—16 weeks after operation (P0.01). Total CaMK Ⅱ activity in hippocampus increased significantly at 4 weeks after operation (P0.01) ,then dropped at 8 weeks after operation, and decreased significantly at 12, 16 weeks after operation (P0.01). In memantine-treated group, at 4 weeks after operation, no statistical difference in the indexes mentioned above was found compared with the sham group, but at other time points, there were significant differences (P0.05,P0.01);besides, the level of NR2B was higher than that of VaD rats (P0.05,P0.01) at 8,12 weeks after operation, but total CaMK Ⅱ activitiy was similar to that of VaD rats. Conclusion The changes of CaMK Ⅱ activities are mainly mediated by NMDAR. Memantine can improve VaD rats' recognition by modulating the expression of NR2B,but its effect on CaMK Ⅱ activities is limited.
【CateGory Index】： R749.1