Aging Changes Of The Arterial Elastic Fibers And The Elastin Mrna Expression In Rat Brain

Aging changes of elastic fibers and the expression oftropoelastn mRNA in the middle cerebral artery of the ratAbstractOBJECT:In order to provide reference for further understanding the etiology and pathogenesis of the certain cerebrovascular disease, the aging changes of the elastic fibers and the expression of tropoelastin mRNA in the middle cerebral artery of the rat were studied.METHODS:Three different age groups of Wistar rats(l-2, 6-7 and >24 months old) were studied by H.E stains, Weigert's resorcin-fuchsin, improved Heidenbain stain methods, electron microscope, oligonucleotides probe in situ hybridization technology and image analysis.RESULTS:(1) An intact layer of internal elastic lamina was composed of elastic fibers, and the folds looked like wave. The number of the folds of internal elastic lamina reduced with age, so as the amplitude. There were some scattered elastic fibers in the media and adventitia and the external elastic lamina was absent. (2)The relative content of the elastic fibers decreased significantly(p24 months old group, and the internal elastic laniina branched into media and the lipid deposited in the internal elastic lamina. Endothelial cells and smooth muscle cells passed through the internal elastic lamina, the number of the collagenic fibers increased. (4)Tropoelastin mRNA expressed in cytoplast of endothelial cells smooth muscle cells and fibroblasts, and decreasingly with age(p