Changes of elastic fibers of middle cerebral artery in rats with various ages

Objective: To study the changes of the elastic fibers of middle cerebral arteries in the rat of various ages.Methods:The different age groups of rats were studied by light microscope,electron microscope and image analysis system.Results:With age,the follwing changes happened:the number and the protruding folds of the internal elastic lamina reduced;the content of the elastic fibers decreased significantly( P 0.01);the ratio of collagenic fibers to elastic fibers decreased significantly( P 0.01).The internal elastic lamina thinned,delaminated and disrupted in the groups aged 24 months,and the lipid deposited in it.Endothelial cells and smooth muscle cells passed through the internal elastic lamina.Conclusion:The changes of the elastic fibers may be related to the increased susceptibility to the cerebrovascular disease in aging.