Abstract:

To investigate the effect endothelial progenitor cells (EPC) in combination with estrogen on restenosis after percutaneous coronary intervention． MethodsSixty New Zealand white rabbits were randomly divided into five groups: the sham operation group(groupⅠ), the control group(groupⅡ), the estrogen treated group(groupⅢ), the EPC treated  group(groupⅣ), and the estrogen in combination with EPC group(groupⅤ)， with twelve rabbits in each group. Three days after ovariectomy, animals in groups Ⅲ and Ⅴ were treated with estrogen, and the others were given physiological saline. The level of estrogen was detected before ovariectomy, and on  day 3 and 2 weeks after ovariectomy. Levels of blood lipids(including total cholesterol, triglyceride, high density lipoprotein choesterol and low density lipoprotein cholesterol) were also detected after hyperlipemia feeding for 6 weeks. Mononuclear cells were isolated from the establishing animal models of injured abdominal aorta, animals in the shamoperation group had the femoral artery exposed without injuries. At the same time, rabbits in groups Ⅳ and Ⅴwere subjected to  suspension of EPC at 2ml through a catheter and the others（except Ⅰ group） were given physiological saline. Endothelium recovery, degree of cell proliferation and lumen loss were evaluated after 4 weeks. ResultsThe level of estrogen in groups Ⅲ and Ⅴwere obviously higher than that in groupsⅠ, Ⅱ and Ⅳ（P＜0.01）. The levels of blood lipids, including total cholesterol(P＜0.01）, low density lipoprotein cholesterol(P＜0.01）and  high density lipoprotein choesterol(P＜0.05）were statistically different between groups Ⅲ,　Ⅴ and groupsⅠ, Ⅱ Ⅳ. There were also a statistical significance in the degree of endothelium recovery, cell proliferation and lumen loss between group Ⅴ and groups Ⅲ,　Ⅳ［(90.2±5.1)% vs (85.1±4.1)% and (83.9±6.5)%，P＜0.05］，　［(15.67±2.98)% vs (26.02±4.18)% and (24.87±3.54)%，P＜0.01］, and ［( 17.61±2.69)% vs (38.43±4.35)% and (41.15±4.45)%，P＜0.01］. ConclusionEPC in combination with estrogen after PCI can speed up the process of endothelial recovery and significantly reduces lumen loss.

Key words: Endothelial progenitor cells; Estrogen; Restenosis; Endothelialization; Neonitima proliferation; Rabbits