Influence Of LPS-induced Adventitial Inflammation On Intimal Proliferaion Of Rabbit Femeral Artery And Its Possible Mechanism

Objective Atherosclerosis is considered an inflammatory disease, which has been indentified as macrophages and lymphocytes were found in plaque. Recently, studies have shown inflammatory reaction was not only in intima ,but in the early stage of atherosclerosis, inflammatory cells were found in adventitia, and adventitial inflammation contributed to intima proliferation and occurrence of acute coronary syndrome.The present study used lipopolysaccharide to induce adventitial inflammation of rabbit femeral artery,and investigated the influence of adventitial inflammation on intimal prolifration,and used NF-кB p65 as marker of inflammation to clarify the molecular mechanism of it.Methods: Twenty -four New ZeaLand white rabbits weighing 1.5-2.0Kg were used,the rabbits were placed on a 1.5%Cholesterol diet for 2 weeks.The right and left side of each animals femeral artery were randomly divided into two groups: lipopolysaccharide group and control group. During the surgery ,a nonconstrictive polyethylene cuff was placed loosely around the femeral artery of the rabbit ,between the artery and the cuff, a sterilized cotton thread was placed ,the thread previously soaked overnight in 6g/ml lipopolysaccharide in saline for 24 hours. The other femeral artery was used as control with nomal saline instead of lipopolysaccharide. Animals were killed at intervals of lhour(n=8), 3days(n=8) and 2weeks(n=8) after surgery. The morphology of the artery and the immunochemistory expression of NF-icBp65 in the artery were investigated.Results: In lipopolysaccharide group,3 days after surgery, inflammation cells migratedinto artery from both the luminal and adventitial side, and inflammation reaction lasted to 2weeks. NF-KB p65 was expressed in endothelium and adventitial cells 3days after surgery inlipopolysaccharide group. Adventitial inflammation resulted in a larger intimal area( 0.93 0.14mm2 ) in lipopolysaccharide group, compared with control group(0.75 0.15mm2) (P<0.05 ) 14 days after surgery.Conclusion: lipopolysaccharide -induced adventitial inflammation contributes to intimal proliferation, and the activation of NF-кB in endothelium and adventital cells leading to the migration and proliferation of smooth muscle cells may be the mechanism of it.