Abstract:Vascular calcification is an active,cell-regulated process,characterized by the deposition of hydroxyapatite crystal in vascular wall,resulted from high-calcium/phosphate-environment,up-regulation of mineralization inducers and down-regulation of mineralization inhibitor in local or systemic sites.In this process,the protective system against vascular mineralization is exhausted,and mesenchyma,such as vascular smooth muscle cells(VSMC),lose the intrinsic phenotypes,but gain the osteogenic phenotypes.Consequently,mineralized cells release some lipid vesicles,which have two forms at least in vascular wall,such as matrix vesicle and apoptosis body.Lipid vesicles provide appropriate nucleating micro-environments for vascular calcification,and vascular elastin provides the bracket structure for hydroxyapatite deposition.So,under the condition that the balance between calcium deposition(mediated by osteoblast-like cells)and calcium absorption(mediated by osteoclast-like cells)is disrupted,ectopic calcification of vascular intima,media or aortic valve may be developed.Intervention on the mechanisms and risk factors of vascular calcification may bring some beneficial effects on the reverse and regression of vascular calcification.In particular,up-regulation on the number and activity of osteoclasts or osteoclast-like cells in calcification lesion may be a more efficient therapeutic strategy.However,it will be a difficult problem in future how to coordinate the relation between normotopic bone formation and ectopic calcification absorption because of calcification paradox in bone-vascular axis.

Abstract:Aim: To study the morphological and quatitative change of elastic fiber in different stages of atherosclerotic lesions.Methods: The normal intima, fatty streaks and fibrous plaques, from 17 abdominal aortae of young men of nom-cardiovascular sudden death were observed with electrolic microscope.Results: The elastlc flber in normal intima appeared to be cord-like, while the e1astic fiber in the fatty streaks and fibrous plaques appeared to be patch-like.The content of elastic fiber was highest ln the fatty streaks, the lowest in the fibrous plaques. The elastic fiber content of normal intima was between the fatty streaks and fibrous plaques. The differences of elastic fiber content among three groups were statistically significant (P<0. 01 ).Conclusion: With the developement of atherosclerosls, the elastlc fiber has not only morphological changes but also content change. This indicate that the elastic fiber plays a very irnportant role in the formation and developement of atherosclerosis.