水溶性壳聚糖对腹主动脉球囊损伤大鼠血管狭窄的抑制作用

摘 要］ 目的:探讨水溶性壳聚糖（WSC）在血管狭窄方面的作用，阐明WSC对大鼠腹主动脉球囊损伤的影响，为开发防治血管狭窄的高效低不良反应药物提供实验依据。方法：75 只雄性 SD大鼠随机分 5 组：50、100和 200 mg/kg 的WSC 组、模型组和对照组（假手术组），每组15只。采用球囊损伤大鼠腹主动脉内膜方法制备血管狭窄模型，对照组仅分离结扎右髂总动脉。造模后WSC各组经大鼠尾静脉分别注射50、100 和 200 mg/kg浓度的 WSC；模型组和对照组注射生理盐水，每次0.4 mL，每天1次。每组按 7、14 和 21 d 3个时点随机选取 5 只大鼠处死，常规HE染色制作病理切片，观察各组大鼠血管损伤形态，计算相对管腔面积，比较 WSC 对血管狭窄的抑制作用。结果：普通光学显微镜观察，对照组大鼠腹主动脉结构完整，中膜血管平滑肌细胞排列整齐。模型组大鼠在第7天时腹主动脉血管内膜增生明显；第14天时可见内膜、中膜明显增厚，管壁局限性隆起；第21天内膜增厚，以平滑肌细胞为主，中膜细胞排列紊乱，有假腔形成。与模型组比较，实验组第7天时内膜增生明显减轻，以100 和 200 mg/kg WSC组为最好；第14天时可见内膜、中膜增厚均不明显，但200 mg/kgWSC组仍可见大量排列紊乱的血管平滑肌细胞；第21天时各浓度的WSC组均表现正常，其中以200 mg/kg WSC组更为明显。管腔相对面积比较，对照组大鼠管腔面积随术后时间变化不明显（P>0.05）；模型组大鼠管腔面积在第7、14 和 21天时均减小，与对照组比较差异有统计学意义（P<0.01）。50 mg/kgWSC 组大鼠在第 14 天和第21天时，管腔面积有一定的增加，但与对照组比较差异有统计学意义（P<0.01）；100 mg/kg WSC组大鼠的管腔面积明显大于 50 mg/kg WSC 组，其中在第14 天和第21天时的管腔面积与对照组比较差异有统计学意义（P<0.05）；200 mg/kg WSC 组的管腔面积在多于 14 d时为最大，与对照组相比较差异无统计学意义（P>0.05）。各实验组不同天数之间比较差异均无统计学意义（P>0.05）。结论：WSC对大鼠腹主动脉球囊损伤后的血管狭窄有明显抑制作用，其中以200mg/kg浓度的 WSC作用14 d以上为抑制作用最强。

Inhibitory effects of water-soluble chitosan on angiostenosis of aorta ventralis of rats with balloon injury

Objective To explore the effects of water-soluble chitosan(WSC)on angiostenosis and balloon injury of rat aorta ventralis,and to provide the basis for the development of high efficiency and low side-effect drug on prevention of angiostenosis.Methods Seventy-five SD male rats were randomly divided into five groups: 50,100 and 200 mg·kg-1 WSC groups,model group and control group(n=15).The angiostenosis animal model was established by balloon to injure rat aorta ventralis.The right common iliac artery was ligated for the rats in control group.After establishing the animal model of angiostenosis,the WSC of 50,100 and 200 mg·kg-1 concentrations was respectively injected into vena caudalis of the rats in WSC groups,and normal saline were injected into vena caudalis of the rats in model group and control group,0.4 mL every time and 1 time every day.At the 7th,14th and 21st days after the operation,five rats in each group were randomly sacrificed,aorta ventralis were obtained and their pathological sections of HE dyeing were prepared.The pathological changes of blood vessel in each rat were observed with microscope and the ratios of lumina area to extima area at different time were counted.The inhibitory effects of WSC on angiostenosis were compared among five groups.Results Under microscope,a complete structure of aorta ventralis was observed and smooth muscle cells of tunica media were arranged in order in control group.In the aorta ventralis of the rats in model group,obvious proliferation of intima was observed at the 7th day after the operation,thickening tunica intima,thickening tunica media and localized proliferation of vessel wall were also observed at the 14th day after the operation,and many smooth muscle cells in thickening tunica intima were discovered,and smooth muscle cells of tunica media were arranged disorder and false lumen was formed at the 21st day after the operation.Compared with model group,at the 7th day after the operation,the proliferation of tunica intima was obviously lessen in experiment group,and especially in 100 and 200 mg·kg-1 WSC groups.At the 14th day after the operation,thickening tunica intima and media were not obviously observed,but in 200 mg·kg-1 WSC group,large smooth muscle cells with disorder arrangement were still visible in tunica media.At the 21st day after operation,the vessel wall of aorta ventralis was normal in all WSC groups,especially in 200 mg·kg-1 WSC group.The comparison of the relative lumen area showed that the variation of the relative lumen area of the rats in control group did not change significantly following the time after operation(P>0.05);but compared with control group,the lumen area variation of the rats in model group at the 7th,14th and 21st days had very significant difference(P<0.01).50 mg·kg-1 WSC could enlarge the lumen area of the rats at the 14th and 21st days,but compared with control group,the difference was still very significant(P<0.01).100 mg·kg-1 WSC could enlarge the lumen area better than 50 mg·kg-1 WSC did;and at the 14th and 21st days,the difference between WSC groups and control group was still significant(P<0.05).200 mg·kg-1 WSC was the best concentration on the enlargement of the lumen area after 14 d,and there was no significant difference compared with control group(P>0.05).Compared between the different days of all groups,there were no significant differences(P>0.05).Conclusion WSC could significantly inhibit the angiostenosis after balloon injury of rat aorta ventralis and the inhibitory effect could be the best at the concentration of 200 mg·kg-1 and more than 14 d.