Quantitative Research For Metabolites By 9.4T~1H-MRS In Hippocampus Of Alzheimer's Disease Mice

AIM:To study Alzheimer's disease mice caused by the D-galactose and NaNO2, observe the alteration of hippocampal metabolites using in vitro 9.4T high resolution magnetic resonance spectroscopy.METHODS:Twenty kunming mice were randomly divided into two groups, model group and control group. Female to male ratio was 1:1. The mice in the model group were subcutaneouly injected with D-galactose 120 mg/(kg. d), NaNO290 mg/(kg. d) for 60 days and the control group with oral saline.24 hours later after Morris water maze test, all mice were sacrificed and the right hippocampus were dissected for 'H-MRS examination. Data were collected using in vitro 9.4 T high resolution magnetic resonance spectrometer. Spectra were processed using XWINNMR and MestRe-c 4.3. Compared with the left side, HE and Bielschowsky silver impregnation and congored coloration were employed to detect and confirm the change of brain cells.RESULTS:Good'H-MR spectra of perchloric acid extract from hippocampus tissue of mice were obtained. The conventional metabolites were detected and assigned. Mean concentrations of metabolites in control group and model group were, NAA: 43.63±7.67 mmol/L and 34.66±6.79 mmol/L; Cho:53.09±4.32 mmol/L and 48.62±7.92 mmol/L;Glu:26.87±5.46 mmol/L and 14.87±2.68 mmol/L;ml:45.93±6.73 mmol/L and 74.09±8.09 mmol/L, the differences of two groups were statistically significance(P<0.05). Results of Morris water maze behavior examination were as: the escape lateney and the movement distance percentage and time percentage were significant difference between control group and model group (p<0.05). The neurons in control group were intact and arrange tightly. In the model,pyramidal neurons either presented a densely stained shrunken appearance with minimal cytoplasm or had disappeared; Bielschowsky silver impregnation, many neurofibrillary tangles were found, and neuropil threads are stained in model group. Congored coloration result:in the cerebral cortex and hippocampal fields, orange amylaceous aggradation can be seen.CONCLUSION:D-galactose and NaNO2 can cause the mice induce Alzheimer's disease in vivo. High resolution 1H-MRS in vitro can detect diversified metabolism. In the model group the hippocampal concentrations of NAA,Cho,Glu are decrease. The changing trend for mI is increase.