Changes of elastic fibers in middle cerebral artery of different aging rats / 中国组织工程研究

ABSTRACT

BACKGROUND: Changes of elastic fibers in middle cerebral artery(MCA)is close related withthe aged cerebrovascular disease.OBJECTIVE: To observe the changes of elastic fibers of MCA in different aging rats.DESIGN: A descriptive and controlled study based on experimental animals.SETTING: Department of anatomy and central laboratory in a university.MATERIALS: Totally 36 healthy Wistar rats with either gender, weighing 200 - 280 g, were selected from the Animal Institute of the third medical military university of Chongqing[certification SCXX (army) 2002-007].INTERVENTIONS: Changes of elastic fibers of MCA of different aging rats were observed with light microscope, transmission electron microscope and image analysis system. MAIN OUTCOME MEASURES: ①) Major outcome: changes of elastic lamella in MCA of different aging rats; ②) Secondary outcome: ultramicrostructural changes of internal lamella under the transmission electron microscope. RESULTS: With the increase of age, the folded extent and quantity of internal elastic lamella were decreased, and the content of elastic fibers were also decreased significantly( P ＜ 0.01 ). However, the ratio of collagen fibers to elastic fibers was increased significantly( P ＜ 0.01 ) . In the aging group above 24 months, the internal elastic lamina thinned, delaminated and disrupted, and the lipid deposited in it. Endothelial cells and smooth muscle cells passed through the internal elastic lamina. CONCLUSION: Changes of elastic fibers may be related with the increased susceptibility to the cerebrovascular disease in aged people.