高血压大鼠脑部MRI表现及免疫组织化学研究

MRI characteristics and immunohistochemical study of the brain of the hypertensive rats

目的:探讨慢性高血压鼠颅脑MRI表现的演变和免疫组织化学特点,旨在提高对高血压引起慢性脑损害的认识。方法:成年SD大鼠28只,随机分成正常对照组10只和高血压模型组18只,术前及术后每间隔2个月测量鼠尾血压并行MR扫描,同期两组随机各处死1只,进行鼠脑MBP免疫组织化学染色,观察其免疫组织化学变化。结果:正常对照组大鼠MRI表现均正常,髓鞘结构呈团状,结构紧密,边界规整;高血压大鼠术后最早第8个月开始,MRI图像上出现侧脑室扩张,其尾壳核区域神经胶质细胞变性和少许髓鞘空泡;而脑室旁线条状高信号影,其尾壳核区域可见胶质细胞变性增生,髓鞘层次紊乱。结论:慢性高血压大鼠直到鼠龄较大时,尾壳核区域出现明显的髓鞘变性,才在MRI上显示出来。

Objective：In order to recognize the brain chronic damage due to hypertension further, the evolution of MR imaging and immunohistochemistry in hypertensive rats were assessed. Methods：28 adult SD rats, after killed one, others were grouped normal （n= 10） and hypertension （n= 18） at random. Before and after operation, we measured the blood pressure of the tail artery and performed MR scan every two months. During the mean time, one rat was killed in every group. The immunohistochemistry changes of rat brain was observed by MBP staining. Results： In normal group, MRI findings of rats brain were normal. In hypertensive group, enlargement of lateral ventricle from the 8th month. The immunohistochemical changes observed in periventricular caudate putamenarea were degeneration of gliocyte, a little vacuolar in myelin sheath. The strip shape hyperintensity at paraventricle which was detected on the MRI was characterrized by degeneration and proliferation of glineytes, degeneration of myelin sheath. Conclusion：There are obviously immunohistochernistry changes and abnormal MRI finding in caudate putmanarea only in older rats with chronic hypertension.