Abstract:

Abstract: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 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 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 WSC groups.At the 14th day after the operation, thickening tunica intima and media were not obviously observed, but in  200 mg/kg WSC group, large smooth muscle cells with disorder arrangement werestill 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 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 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 WSC could enlarge the lumen area better than 50 mg/kg 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 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 and more than 14 d.

Key words: water-soluble chitosan;rats,Sprague-Dawley;abdominal aorta, balloon injury, angiostenosis