Effects of Simvastatin and rhG-CSF on Endothelium Repair in Balloon-Injured Common Carotid Artery of Rabbits

Objective: To investigate the effects of simvastatin and recombinant human granulocyte colony stimulating factor(rhG-CSF) on the changes in vessel wall and peripheral blood CD34+content after rabbit carotid artery intima injury.Methods: 48 male New Zealand white rabbits were randomly divided into four groups: single injury group,simvastatin group,rhG-CSF group and combined with simvastatin and rhG-CSF group(combined group).After injury the left common carotid artery intima balloon-catheter,simvastatin 10 mg·kg-1·d-1 was pushed into stomach in the simvastatin group,and rhG-CSF 100μg·d-1 was given via subcutaneous injection in rhG-CSF group and combined group,2ml venous blood was drawed at pre 1d,after 7d,14d,21d,28d each group,then CD34 +cell levels in peripheral blood were analyzed by flow cytometry,4 weeks later all animals were killed.The specimens of artery tissue were dyed by elastic fibers staining and HE staining,and the changing of intimal thickness,medial thickness,lumen area(S),intimal area(Si),medial area(Sm) and the Si / Sm ratio was evaluated.Results: ① The preoperative peripheral blood CD34+cells in 4 groups had no significant difference(P0.05);After 7d,peripheral blood CD34+ cells in each group was the highest,then decreased gradually,but peripheral blood CD34+cells at 28d was still higher than the preoperative levels;The mean density of CD34+cells at pre 1d,after 7d,14d,21d,28d in rhG-CSF group and combination group was higher than the single injury group(P0.01,P0.01);There was no discrepancy between the simvastatin group and the single injury group at after7d and after14d(P0.05),while there was significant difference between the simvastatin group and the single injury group at 21d and at 28d.(P0.05) ② Compared with the single injury group,Si/Sm of simvastatin group,rhG-CSF group and combination group significantly reduced(P0.05);there was no discrepancy between simvastatin group and rhG-CSF group(P0.05);Compared with the simvastatin group and rhG-CSF group,combination group had less intimal hyperplasia(P0.01,P0.01).Conclusion: Simvastatin could promote injured intimal repair and prevent restenosis.Long-term use of simvastatin can increase the peripheral blood CD34+cells;rhG-CSF significantly increases the peripheral blood CD34 +cells and prevents stenosis;Simvastatin and rhG-CSF combination therapy significantly increases the peripheral blood CD34+cells,accelerates endothelial repair and prevents restenosis,compared with single drug there is better efficacy.