Correlating endothelial cell functions and histomorphology to hyperlipemia / 中国组织工程研究

ABSTRACT

BACKGROUND: Autologous vein transplantation is a common means for clinical treatment of coronary atherosclerotic heart disease. Identification of basic pathological changes of autologous vein transplantation will provide basis for further studies on how to protect transplanted vein and reduce the possibility of restenosis of transplanted vein.OBJECTIVE: This study was designed to investigate effects of hyperlipemia, an independent influential factor, on venous endothelial functions and histomorphology.DESIGN, TIME AND SETTING: This study, a randomized controlled animal experiment, was performed at the key laboratory of Department of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University of Chinese PLA.MATERIALS A total of 50 healthy adult male rabbits were randomly and equally divided into a control group and a hyperlipemia group.METHODS: In the control group, rats were daily fed with normal diet 100-120 g. In the hyperlipemia group, rats were daily fed with normal diet 100-120 g plus cholesterol 1g. For all rats, water was freely available.MAIN OUTCOME MEASURES: Prior to and 2,4,8, and 12 weeks after feeding, blood sample and cervical vein specimens were taken for detection of blood lipid levels and observation of endothelial nitricoxide synthase (eNOS)expression, nitric oxide (NO) production, and histomorphologic change. Prior to harvesting vein sample, blood flow of jugular vein and carotid artery was examined using ultrasonic Doppler flowmeter. Simultaneously, histopathological changes including the thickness of intima and media, the diameter of the veins, and the presence of lipid or atherosclerotic plaque were observed.RESULTS: Eight weeks after feeding, blood lipid levels in the hyperlipemia group were significantly higher than those prior to feeding and in the control group (P<0.01), and maintained at this level. Obvious lipid plaques formed in the carotid artery of rabbits in the hyperlipemia group. Eight and twelve weeks after feeding, eNOS expression levels and NO production in the jugular veins were lower than those prior to feeding and in the control group (P<0.05). Simultaneously, endothelial denudation was noticed and the elastic fibers almost disappeared in the hyperlipemia group; there were no foam cells or lipid plaques.CONCLUSION: Hyperlipemia may result in endothelium dysfunction and histomorphological change of venous conduit.Nevertheless, autogenous vein transplanted into artery system, will greatly influence the remodeling of transplanted vein,even lead to restenosis of transplanted vein.