| Objective: With the successful establishment of D- galactose induced subacute aging animal model, rats were moderate load and aerobic exercise intervention in pre-model and modeling process to explore different periods of aerobic exercise on aging.Methods: Adult male 3-month-old SPF SD rats, 60, 400 ± 20 g. Control group(C group), Aging model group(A group), Exercising before the modeling group(E1 group), Exercising in the modeling group(E2 group). In addition to C group, the remaining rats were used "by intraperitoneal injection of D- galactose".Before modeling E1 group carried out during moderate load swimming exercise, E2 group did in the modeling, C group did not. The end, decapitated, stripped, stored into liquid nitrogen.Observed, Recorded, Nissl staining; immunofluorescence, Real-time PCR, Western Blotting, DNA methylation, Analsis. Results:(1) The the general state: C group rats good mental state, agile, eating normal, uniform and shiny hair, body robust; A group appear lethargy, drowsiness, brown curly hair, and other aging signs; E2 group were similar to C group; E1 group were worse than E2 group. Four weeks before the weight were steady growth, no significantly difference(P> 0.05); In addition to group C, the others' growth slowed to varying from the fifth week; the changes in tenth weekend trends: C group >E2 group> E1 group> A group.(2) Nissl staining: In C group, the hippocampal neurons neat, and dendrites Nissl colored uniform, complete cell structure; In A group, the hippocampal neurons element disorder, some neuronal nuclei blurred, the cell structure is not complete; E1 ? E2 group was respectively close to in A group and C group.(3)Immunofluorescence staining: IOD values of Syp: A group and E1 group were very significantly lower than in C group(P<0.01), E1 group was significantly higher than group A(P<0.05), E2 group was significantly higher than group A(P<0.01), E2 group very significantly higher than A group and E1 group(P<0.01); IOD values of mGluR1:A group were very significantly lower than in C group(P<0.01), E1 group were significantly lower than in C group(P<0.05),E1 group was significantly higher than group A(P<0.05), E2 group was significantly higher than group A(P<0.01), E2 group very significantly higher than A group and E1 group(P<0.01).(4) Real-time PCR and Western Blotting : Compared with C group, A group was significant higher(P<0.01); E2 group and very significant lower than that in group A and E1 group(P<0.01).(5) DNA methylation : 5 sites methylation levels vary, but the changes between the various sites of approximately the same trend, C group, E2 group have a relatively high level of methylation, A group, E1 group relative methylation levels lower; A group, E1 group methylation levels are relatively low.(6) Analysis: Syp IOD and PDE-4 mRNA showed asignificant negative correlation(P<0.01), and PDE-4 expression were significantly negatively correlated(P <0.05); mGluR1 IOD with PDE-4 mRNA and protein expression showed a significant negative correlation(P<0.01). 151 and 225 levels and PDE-4mRNA and protein expression, methylation point showed a significant negative correlation(P<0.01); Conclusion:(1) Aerobic exercise repairable morphology of hippocampal neurons, and so Syp mGluR1 number and density is maintained at a certain level, the ability to maintain synaptic plasticity, improve brain function, slow down brain aging;(2) Aerobic exercise can PDE-4 gene hypermethylation, thereby enabling the gene inactivation by down-regulating the expression of mRNA and protein, reduce the inhibition of downstream gene pathway. It may be speculated that aerobic exercise repair hippocampal neurons morphology, synaptic plasticity, the ability to maintain and improve brain function, slow down one of the possible mechanisms of brain aging;(3) The different periods of aerobic exercise on brain aging intervention were different. Aerobic exercise intervention in the aging process performed relatively well. Tip: sustained aerobic exercise need to better play its role... |
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