Structural Variations in Aortic Intima According to Age

Abstract

Amac : Bu calismada, aorta duvarinda yasin ilerlemesine kosut olaylanan yapisal degisikliklerin belirlenmesi amaclandi. Yenidogandan baslayarak belirli yas gruplarini kapsayan doku orneklerinde yasin ilerlemesiyle, elastik liflerin, dagilimi, yogunlugu, dizilimleri, yapisal ozellikleri, kalinliklari ve sayisal degisimleri ince yapi duzeyinde incelendi. Yontemler : Bu calismada kullanilan aorta doku ornekleri Ankara Ibni Sina Hastanesi’nden saglanan sicanlardan elde edildi. Disi, Wistar-albino cinsi sicanlar; yenidogan, 5 hafta, 7 hafta, 3 ay ve 1 yas olmak uzere bes farkli yas gruba ayrildi. Sicanlarin agirliklari ortalama; yenidoganlar 4,5-6 g, 5 haftalik olan grup 110 g, 7 haftalik olan grup 130 g, 3 aylik olan grup 220 g ve 1 yasinda olan grup 350 g olarak belirlendi. Her gruba ait aorta ornekleri alinarak, elektron mikroskobik izleme yonteminden gecirildi. Gruplardan alinan dokular Gecirmeli Elektron Mikroskop (TEM)’da ve toluidin mavisi ile boyanan yari ince kesitler isik mikroskopta degerlendirildi. Bulgular : Isik mikroskobu ve TEM ile yapilan incelemelerde yaslanma ile birlikte internal elastik laminanin belli bir sure kalinlastigini ancak daha da ileri yaslarda incelmeye basladigini belirledik. Genc sicanlarda pinositotik vezikullerin hem bazalde hem de apikal yuzde hemen hemen esit oldugunu, ileri yastaki sicanlarda ise; vezikullerin apikal yuzde yogunlastigini ve endotel hucrelerinin duzensiz sekilli oldugunu izledik. Yasa kosut olarak duz kas hucre proliferasyonunun arttigini, internal elastik lamina bolgelerinde bu hucre artisinin belirginlestigini saptadik. Sonuc : Yaslanma, aortada, intima ve elastik lamellerin incelmesi ve bunun yerine elastik lifler arasinda bag dokusu ve kas hucrelerinin artisi, endotel hucrelerinde bozulma ve bazi bolgelerde dejenerasyonlarinin gozlemlendigi, organel ve organlarin aktivitelerinin yavasladigi ya da bozuldugu oldukca karmasik bir olaydir. Sonuc olarak aortanin yaslanma ile dejenerasyona ugradigi tespit edilmistir. Anahtar Kelimeler: Aort, yaslanma, TEM Structural Variations in Aortic Intima According to Age Objective : The purpose of this study is to examine the structural variations in aortic wall according to age, including a specific age group in the age spectrum using newborn tissue samples The distribution, density, sequences, structural characteristics, thickness and quantitative changes of the elastic fibers were examined ultrastructurally. Methods : The aorta tissue samples used in this study were taken from rats supplied from Ankara Ibni Sina Hospital. The female Wistar-albino rats were selected from five different age groups, which are- infants, 5 week, 7 week, 3 months and 1 year. The average weights of the rats were determined as 4,5-6 gr for infants, 110 g for 5 week age group, 130 g for 7 week age group, 220 g for 3 month age group and 350 g for 1 year age group. The aorta tissue samples from all age groups were prepared for electron microscopy method. The half thin sections were stained with toluidine blue for light microscopy and the tissues stained with osmium for Transmission Electron Microscope were also evaluated. Results : In the investigations with light microscopy and TEM, the internal elastic lamina was thickened for a while and in older ages it became thinner. We observed that pinocytotic vesicles of young rats in both the basal and apical cell membrane were almost equal and in older rats the vesicles on apical surface were concentrated and the endothelial cells became irregular. Depending on age, the proliferation of smooth muscle cells increased, and significant increase of smooth cells were found in internal elastic lamina. Conclusion : Aging is a very complex process, in which it is observed that intima and elastic lamels in aorta become thinner, the connective tissue and muscle cells increase between elastic fibers, distortion and degeneration occur in some places in endothelial cells and the activities of organelles and organs decelerate or distort. In conclusion, it was determined that aorta was degenerated by aging. Key Words: Aorta, aging, TEM