Establishment Multiple Alzeimer's Disease Rat Model And Study On The Mitochondrial Pathway Of Neuronal Apoptosis

Objective:According to the Aβ1-42 and D-galactose induced aging theory ,on the basis of subacute aging model,established a multiple Alzheimer disease animal model through injecting Aβ1-42 to lateral ventricle. Based on this, the relationship was observed between the mitochondrial pathway of neuronal apoptosis and thioredoxin. The way provide the scientific theoretical evidence for the pathogenesis of neurodegenerative diseases and clinical prevention.Methods:(1) Injected Aβ1-42 to lateral ventricle established a single factor AD model(B group),adopting injected D-Galactose peritoneally for SD rats established subacute aging model(C group),injected D-Galactose peritoneally combined with injected Aβ1-42 to lateral ventricle established a multiple Alzheimer disease animal model(D group),nomal rats as the control group(A group).(2) Behavior test ability of studying memory in rats, through the water maze experiment.(3) Toluidine blue staining to observe the neuron morphology and the number of changes.(4) Biochemistry test the Catalase,total antioxidant capacity and GSH/GSSG in serum and brain tissue homogenate.(5) Immunohistochemistry detection the expression of aged-associated protein AGEs and AGER,Trx,Cyto-C and caspase-9 in each area of brain tissue observed by immunohistochemistry and Western blot.Results:(1) Study of behavior experiment showed that compared with Agroup, the ability of B group,C group,D group memory significantly decreased(P<0.05 or P<0.01 ); Compared with Bgroup and D group, the ability of memory in D group significantly decreased(P<0.01); (2) Toluidine blue staining showed that compared with A group, the number of neurons stained in B group, C group and D group have different degrees of reduction. The difference was statistically significant (P<0.05 or P<0.01).There are morphological changes of aging such as nuclear condensation, smaller of the cells. This situation with D group is most obvious, followed by B group, the third, C group.(3) Biochemical tests showed that compared with A group, the CAT,T-AOC of serum and brain tissue and GSH / GSSG of serum in B group, C group and D group decrease obviously. The difference was statistically significant(P<0.05 or P<0.01); Compared with B group and C group, the CAT,T-AOC of serum and brain tissue and GSH/GSSG of serum in D group decreased significantly(P<0.01).(4) Immunohistochemistry results showed that compared with A group, the expression of AGEs and AGER in cortex, hippocampus and cerebellum of Bgroup,C group and D group increased significantly(P<0.05 or P<0.01); Compared with B group and C group, the expression of AGEs and AGER in cortex, hippocampus and cerebellum of D group increased obviously (P<0.01) .(5) Immunohistochemistry and Western blot Detection showed that Compared with A group, the expression of Trx decreased, but the expression of Cyto-c and caspase-9 increased in cortex, hippocampus and cerebellum of B group, C group and D group, The difference was statistically significant(P<0.05 or P<0.01); Compared with B group and C group, the expression of Trx decreased, but the expression of Cyto-c and caspase-9 increased in cortex,hippocampus and cerebellum of D group,there was a significant difference(P<0.01).Conclusion:(1)It is more successful in establishing a multiple Alzheimer disease animal model on the basis of aging, preliminary study the potential relationship between aging and AD.(2)On the basis of D-galactose subacute aging model, established the multiple Alzheimer disease animal model with beta-amyloid. The behavior, biochemical indicators and histological of the multiple Alzheimer disease model is superior to single factor Alzheimer disease animal model. The AD multiple modle not only can be used to basel research of the old dementia. But also can be used to investigate the prevention and cure of the old dementia.(3)Combined the D-galactose with beta-amyloid established the multiple Alzheimer disease animal model, the expression of AGEs and AGER increased significantly. The increasing of AGEs and AGER can accelerate the process of incidence of AD in turn. The inhibitors of AGEs and AGER might be of clinical research drug targets for AD.(4)In different model group, the expression of Trx decreased in varying degrees. Cyto-C, Caspase-9 which is important protein of mitochondrial apoptosis pathway decreased.The expression of Trx had negative correlation with the expression of caspase-9 and cyto c,and The expression of cyto c had positive correlation with the expression of caspase-9. Suggesting decline of Trx in AD and the occurrence of apoptosis has important links and there may be through Cyto-C release and activation of Caspase-9 caused apoptosis.