甲氨蝶呤抑制兔颈动脉球囊损伤后新生内膜形成

目的　探讨不同剂量甲氨蝶呤 (MTX)对血管损伤后新生内膜形成的影响。方法　制备兔颈动脉球囊损伤模型 ,动物随机分为对照组、MTX 0 5mg/kg、MTX 1 5mg/kg及MTX 5mg/kg组 ,每组 5～ 8只 ,采用肌肉注射方式给药 ,于术后 2周和 4周取材 ,分别进行伊文思染色观察内皮覆盖情况、增殖细胞核抗原 (PCNA)免疫组化染色和定量组织形态学分析。结果　MTX治疗组血管内膜面积、内膜 /中膜面积比值均显著低于对照组 ,内膜面积抑制率达 4 6 %～ 5 6 %,不同剂量MTX之间差异无显著性。内膜及中膜PCNA阳性细胞数目较对照组减少。伊文思蓝染色显示各组间内皮修复程度差异无显著性。结论　MTX能够有效地抑制球囊损伤后血管平滑肌细胞的增殖和新生内膜形成 ,在一定剂量范围内 ,MTX的作用无明显差异。

The effects of methotrexate on the neointimal formation after balloon injured arteries in rabbits

Objective To study the effect of methotrexate on the neointimal formation after arterial balloon injury. Methods Male rabbits were randomized into four groups: MTX 0.5 mg/kg per week, MTX 1.5 mg/kg per week, MTX 5 mg/kg per week and the control. Drugs were administered by intramuscular injection. Rabbit carotid arteries were harvested 2 and 4 weeks after injury. Results Histologically, the intimal areas were reduced significantly in MTX treated animals compared with the controls. The VSMC proliferation in injured vessels was identified by immunostaining for proliferating cell nuclear antigen (PCNA). In comparison, PCNA-positive cells in both intima and media were significantly reduced by treatment of MTX. But MTX did not enhance reendothelialization in the injured carotid arteries as determined by Evans blue stain.Conclusion Low dosage of MTX could attenuate neointimal formation after arterial injury by inhibiting VSMC proliferation.