慢性肾性高血压大鼠脑组织磁共振成像观察和超微结构的研究

目的研究慢性肾性高血压大鼠脑核磁共振成像(MRI)的变化和相应部位超微结构的改变。方法将SD大鼠分为对照组和模型组。用双肾双夹法建立肾性高血压动物模型，术后饲养12个月，用磁共振成像结合电镜观察大鼠脑组织的变化。结果1．正常组大鼠的血压、MRI表现及超微结构未发现异常。2．慢性肾性高血压模型大鼠血压升高；侧脑室旁尾壳核区域T22WI像上可见明显的条状高信号；髓鞘结构松散，可见轴突与髓鞘间及髓鞘板层间形成宽大的裂隙，部分神经纤维缺失，髓鞘脱落。结论慢性肾性高血压大鼠脑内出现明显的条状高信号，提示脑部神经纤维的病变可能己比较严重。

MAGNETIC RESONANCE IMAGING AND ULTRASTRUCTURAL STUDIES OF BRAIN TISSUE IN THE CHRONIC RENAL HYPERTENSIVE RAT

Objective To study changes in brain magnetic resonance imaging(MRI) and ultrastructures of corresponding area in chronic renal hypertensive rats in order to further recognize the chronic brain damage in hypertension. Methods Rats were divided into the normal group and model group. The chronic renal hypertensive model was established by two renal arteries two clips method. Then two groups have been raised for twelve months. The change of rat brain was observed with MRI, and histopathological observation was performed by electron microscopy. Results 1.In normal group, there were no abnormalities in the blood pressures, MRI and ultrastructures. 2.In hypertensive group, the blood pressures of rats were high. On T2-weighted MRI, strip-shaped prominent high signal intensity was present at caudate nucleus near lateral ventricle. The structures of myelin sheath were loose, and wide gaps appeared between axon and myelin sheath, and between layers of myelin sheath. Partial nerve fibers were lost, and exfoliation of myelin sheath was found near the caudate nucleus.Conclusion The prominent strip-shaped high signal intensity on MRI in rats with chronic hypertension may suggeste a severe lesion in nerve fibers of the brain.;