Study on Arteriosclerosis of Human Aorta

The metabolic changes of a living body are regulated by many factors, so it is important to understand the overall informations. The arterio-sclerosis is characterized by fibrous changes, accumulation of lipids and calcium on the arterial wall. The purpose of the present study is to examine many factors in the artery by multivariate analyses and to clear the changes in arteriosclerosis and the arterial components, relating to the etiology.Aortae obtained from the 178 cases (124 men and 54 women) were examined by histochemical and biochemical methods, and the following results were observed.1) The correlation between the content of the aortic wall components and aging were examined. a) Cholesterol of elastin fraction and the occupied areas by atheroma or calcification increased rapidly at a certain age. b) Both the medial elastin contents and the “polarity” of amino acid residues of elastin fractions in the media and the intima of the artery were kept continuously changing from young to old age. The qualitative and quantitative changes of the arterial elastin fraction occured in the arteriosclerotic artery.2) The amino acids residues of elastin fractions were evaluated by multivariate analyses. a) Each 16 factors of amino acid residues in the intima and the media were studied by principal component analyses. As the results, the non-polar amino acid—glycine, alanine, etc.—residues were shown negative values of eigenvector in the first principal. On the other hand, the polar amino acid—glutamic acid, arginine, etc.—residues were shown positive values. The sample scores of the first principal component indicated total change of amino acid residues of elastin fraction, showing a positive correlation with the intimal and the medial polarity. It was supposed that the polarity implicated to indicate total changing of elastin fraction amino acid residues. b) The 32 factors of the intimal and the medial elastin fractions were examined by principal component analyses. As the typical results, such obvious difference was found between the changing in polar amino acid residues and non-polar ones by the first principal component, and it was true between the changing in the intimal amino acid residues of elastin fraction and the changing in the medial ones.3) The 12 factors were studied by principal component analyses;that is, the intimal and the medial elastin contents, ealstin-cholesterol contents, polarity, desmosine and isodesmosine contents and atheroma and calcification. The following conclusions were obtained.As a result of the eigenvectors of the first and second principal component, it was estimated that each 5 factors of the intimal and the medial aortic layers showed similar change, and it may be suggested that 12 factors changed sequentially and probably pathogenically in the order of the elastin content, cross-linked amino acids, polar amino acids, elasin-cholesterol and atheroma or calcification. The multivariate analyses allow the estimation and correlation of the various informations obtained from the living body in relation to diseases.