Experimental study of chitosan inhibiting vascular intimal hyperplasia of rabbit arteriovenous fistula / 中华肾脏病杂志

ABSTRACT

Objective To investigate the effete of chitosan on rabbit carotid artery internal jugular vein fistula intimal hyperplasia and its regulation on TLR4/NF-κB signaling.Methods A total of 28 New Zealand white rabbits were randomly divided into the control group(n=4),the model group(n=12) and the chitosan group(n=12).Model group and chitosan group rabbits were established respectively carotid artery internal jugular vein fistula models.After AVF surgery,chitosan was smeared on venous blood vessels and anastomosis.After 4,6 and 8 weeks,the rabbits were separately sacrificed and the AVF venous vascular tissues were taken.The pathological changes of AVF venous vascular tissue in each group were observed.The changes of α-SMA were detected by immunohistochemistry method.The mRNA expressions of PCNA and TLR4 in the tissues were measured by Real-time PCR.At the same time,the protein expressions of PCNA,TLR4,MyD88 and NF-κB were detected by Western blotting.The experimental data were processed by two-factor analysis of variance in statistics.Results (1) After 4 weeks,vascular intimal was thicked in mdel group.In intimal hyperplasia,α-SMA was staining,and then proliferation of vascular smooth muscle cell was significant.As time increasing,more intimal hyperplasia shown obviously,the expression of α-SMA significantly increased.Compared with model group,chitosan group significantly reduced the degree of intimal hyperplasia,the level of α-SMA was significantly decreased,vascular smooth muscle cell proliferation was also extraordinarily decreased.(2) Compared with control group,the expression levels of PCNA,TLR4,MyD88 and NF-κB increased with time.The indices of Chitosan group were markedly higher than control group,but significantly lower than model groups.Conclusion Chitosan can inhibit the proliferation of rabbit VSMCs.The mechanism may be concerned in down regulating TLR4-mediated signaling pathway,reducing the possibility of intimal hyperplasia of rabbit AVF venous blood vessels.