The Effects of Chitin/Chitosan on Human Coronary Vascular Smooth Muscle Cells and Endotherium

甲壳素/壳聚糖具有促进植物生长、抑菌、防腐等作用，还可用作止血剂、缝合材料、人工皮肤等。本文研究了甲壳素/壳聚糖对体外培养的人冠状动脉血管平滑肌细胞迁移、增殖和胶原合成的影响。结果1)甲壳素/壳聚糖溶液(甲壳素：壳聚糖=20：80，相对分子质量1000~100万)对人冠状动脉平滑肌细胞的迁移、增殖(用~3H-胸腺嘧啶核苷掺入法)和胶原合成(用~3H-脯氨酸掺入法)具有浓度依赖性抑制作用。然而，甲壳素/壳聚糖溶液(甲壳素：壳聚糖=50：50)和壳聚糖低聚物(n&lt；40)没有观察到这些抑制作用。2)ADP刺激的血小板聚集也呈浓度依赖性抑制。3)甲壳素/壳聚糖溶液(甲壳素：壳聚糖=20：80)凝胶上培养的细胞附着和增殖也受到抑制。3)球囊损伤后立即皮下注射抗坏血酸的甲壳素/壳聚糖溶液(25 mg/kg)，2周后皮下注射(20PSI拔出3次)。4周后，对损伤的髂动脉进行组织学检查。皮下注射甲壳素壳聚糖溶液后，内膜(内膜+中膜)表面积(25.0±/-7.4vs16.2+/-4.9，p&lt；0.01)和内膜/中膜(43.5+/-6.4vs31.3+/-9.9，p&lt；0.01)明显减小。4)血样未见明显不良反应。结论甲壳素/壳聚糖在预防PTCT术后和血管成形术后再狭窄方面有一定的应用价值。

Chitin/chitosan are known to exert promoter action of plant growth, antimicrobial action, antiseptic action, and also used as hemostatic agents, suture materials, and artificial skin, We examined the effects of chitin/chitosan on migration, proliferation of and collagen synthesis by human coronary vascular smooth muscle cells in vitro. We also examined the effects of chitin/chitosan on intimal thickness by using rabbit balloon catheter injury model in vivo.Results 1) Chitin/chitosan solution (chitin : chitosan=20 : 80, molecular weight 1000-one million) solution inhibits migration and proliferation (measured by 3H-thymidine incorporation) of and collagen synthesis (measured by 3H-proline incorporation) by human coronary smooth muscle cells in a concentration-dependent manner. However, these inhibitory effects are not observed by chitin/chitosan solution (chitin : chitosan=50 : 50) and chitosan oligomers (n<40). 2) ADP-stimulated platelets aggregation was also inhibited in a concentration-dependent manner. 3) Attachment and proliferation of the cells cultured on the gel made from chitin/chitosan solution (chitin : chitosan=20 : 80) were also inhibited, 3) Chitin/chitosan solution (chitin : chitosan=20 : 80) resolved in ascorbic acid was given subcutaneously (25mg/kg) twice (immediately after balloon injury, and 2 weeks later) in balloon catheter injury rabbit (three times pull with 20PSI). Four weeks later, injured iliac arteries were examined histologically. The surface area of intima (intima+media) (25.0+/-7.4 vs 16.2+/-4.9, p<0.01) intima/media (43.5+/-6.4 vs 31.3+/-9.9, p<0.01) was significantly reduced by subcutaneous injection of chitin chitosan solution. 4) No obvious adverse effects were observed in blood samples. Conclusion Our data suggest possible usefulness of chitin/chitosan for prevention of restenosis after PTCT as well as after angioplasty.