Changes of ultrastructures of aortic endothelial cells with atherogenesis in rabbit observed by atomic force microscope

Objective To investigate the changes of ultrastructures of aortic endothelial cells with atherosclerosis(AS) in rabbits and to explore the feasibility of observing morphological changes with atomic force microscope.Methods Fifty-six male New Zealand white rabbits were randomly divided into two groups:control group(fed general diet,they were further divided into 4 sub-groups,n=6) and model group(fed diet containing 1% cholesterol,they were further divided into 4 sub-groups,n=8).At the end of the 2nd,4th,6th and 8th week post-diet,the concentration of total cholesterol(TC),low density lipoprotein(LDL),triglyceride(TG) were detected.Then killed the rabbits,scanned and analyzed the midpiece of aorta with atomic force microscope.Results The concentration of TC,LDL,TG of control group had no obvious changes before and after experiment(P0.05).The concentration of TC,LDL,TG of model group at the end of the 2nd,4th,6th and 8th week was higher than pre-experiment(P0.05),and they all were higher than control group(P0.05).The aortic endothelial cells and nanometer-scale structure on their surface could be observed with the atomic force microscope.In control group,it showed that endothelial cells were either ellipsoidal or long fusiform in shape and aligned parallel with blood vessel.Their average size was 11.96 μm×3.72 μm,and the height was 3.34 μm.Many similar granular structures on cell surface were showed whose diameter were about 70～90 nm and height was 9～15 nm.The surface roughness of vascular endothelium cell was(87.24±4.46) nm.In model group the ventricular endothelial cells and their granular structures changed over time in shape,size and alignment.Their surface roughness also was increased when compared with those of control group in the same time.Conclusion It suggests that ultrastructures of aortic endothelial cells changes dynamicly during the processes of atherogenesis.Aotomic force microscope scanning can provided reliable evidences of morphology for atherogenisis.