蛛网膜下腔出血后脑血管痉挛平滑肌超微结构研究

采用盐酸和胶原酶消化动脉外膜的技术，对正常的脑动脉、蛛网膜下腔出血后痉挛的脑动脉及经前列腺素F2α(prostaglandin F2α，PGFZa)处理的脑动脉平滑肌细胞构筑进行研究。结果显示正常平滑肌细胞是梭形的，沿着血管长轴环行分布，细胞间通过突起相连，肌细胞外膜面通常是光滑的；痉挛的脑动脉和经PGF2α处理的脑动脉平滑肌外膜面均出现非常相似的膜皱折和卷曲，肌间隙增宽。透射电镜显示急性痉挛管壁病理变化轻微；迟发性痉挛出现明显病理性超微结构改变。实验结果提示急性脑血管痉挛是由平滑肌收缩引起，病理变化轻微；迟发性脑血管痉挛是血管持久收缩伴病理性超微结构改变。

SMOOTH MUSCLE ULTRASTRUCTURAL STUDY ON CEREBRAL VASOSPASM AFTER SUBARACHNOID HEMORRHAGE

The smooth muscle structures of the normal, cerebral vasospasm arteries following the mimic subarachnoid hemorrhage and Prostaglandin F2a(PGF2a)were observed after removal of adventi-tial connective tissue with HC1 and collagenase. The results suggested that normal smooth muscle cells were spindle-shaped and oriented circumferentially around the vessel. Adjacent muscle cells were closely appposed to each other via fine finger-like projections. The adventitial surface of the muscle cells located in the outermost layer was generally smooth in contour. Smooth muscle cells from both vasospastic cerebral arteries and the arteries contracted with PGF2a had corrugated and folded cell membranes. The interstitial space was widened. Transmission electron microscopic examinations demonstrated that slight pathological changes occurred in the acute spasm, degenerative ultrastructural changes accompanied in the delayed spasm. The results suggested that acute spasm might be mainly due to the vasular smooth muscle contraction, associated with slight pathological changes. The delayed spasm might be due primarily to prolonged smooth muscle contraction accompanied by degenerative ultrastructural changes.