球囊导管损伤后早期动脉平滑肌细胞的增殖

目的：研究动脉硬化早期中膜与内膜平滑肌细胞的增殖。方法：球囊导管损伤大鼠的颈总动脉后在电镜和光镜下观察其形态和生化指标变化。结果：术后24h 5-溴脱氧尿嘧啶尿苷阳性平滑肌细胞出现，阳性细胞率分别于术后第2，5d出现高峰。术后第2，3d迁移细胞的出现率最高。术后第3d,88.8%迁移细胞增殖细胞核抗原阳性。透射电子显微镜下，术后第3d中膜平滑肌细胞特别是内层的为合成型，并且与细胞外基质连接稀疏，基底膜、胶原纤维和弹性纤维被消失。结论：动脉损伤后，中膜平滑肌细胞呈高增殖性，由收缩型转变为合成型，与细胞外基质的结合性降低，中膜弹性纤维、胶原纤维被消化，增生活跃的细胞向内膜的迁移性增高。迁移至内膜的平滑肌细胞呈高增殖性。

Morphologic Observation of Proliferation of Smooth Muscle Cells in the Early Stage After Balloon Injury

Objective: Our aim was the study the proliferation of medial and intimal smooth muscle cells in the early stage of atherosclerosis. Methods: We observed the changes of morphology and biochemistry after balloon catheter injury by using electronic and optical microscope. Results: At 24 hours after operation, BrdU positive smooth muscle cells appeared. The positive cells rate reaches its peak at the 2nd and 5th day after operation respectively. On the 2nd and 3rd day after operation, the migratory cells were the most. On the 3rd day, proliferating cell nuclear antigen was positive in 88.8% of the migratory cells. By using the transmission electronic microscope, we observed that the smooth muscle cells in the tunicae media, specially, those in the intima, were synthetic type. The smooth muscle cells joined to the extracellular matrix loosely on the 3rd days after operation.Conclusion: After the injury of the blood vessel, the smooth muscle cells are hyperplasia. The smooth muscle cells in the tunicae media switch from contractile type to synthetic type. The adhesion of smooth muscle cells to the extracellular matrix decreases. The elastic membrane and the colloid fibrin in the tunicae media are digested. The migration of proliferation active cells to the intima increases. Therefore, the smooth muscle cells migrated to the intima appear hyperplasia.