COMPOSITIONAL CHANGES OF THE CORONARY ARTERIES WITH AGING IN JAPANESE, THAI, AND MONKEYS

Abstract

To examine whether there were differences between different races and between different species in regard to age-related changes of elements and the relationships among element contents in the coronary arteries, the authors investigated the left coronary arteries of Japanese, Thai, and monkeys by direct chemical analysis. After ordinary dissections at Nara Medical University and Chiang Mai University were finished, the left coronary arteries were resected from the subjects. The anterior interventricular branch was used as the left coronary artery. The anterior interventricular branches were also resected from rhesus and Japanese monkeys bred in the Primate Research Institute, Kyoto University. After ashing of the arteries with nitric acid and perchloric acid, the element content was determined by inductively coupled plasma-atomic emission spectrometry. In the left coronary arteries of Japanese, the average content of Ca increased remarkably in subjects in their seventies and thereafter increased in the nineties. In the left coronary arteries of Thai, the average content of Ca increased progressively from the forties to the seventies. The average content of Ca in the seventies was two times higher in the left coronary arteries of Thai than in those of Japanese. The accumulation of Ca in the left coronary arteries of Thai occurred at least 10 years earlier in comparison with Japanese. In contrast, the accumulation of Ca hardly occurred at all in the left coronary arteries of rhesus and Japanese monkeys at old age. Regarding the relationships among element contents in the left coronary arteries of Japanese and Thai, significant direct correlations were found among the contents of Ca, P, Mg, Zn, and Na, whereas significant inverse correlations were found between S and element contents, such as Ca, P, Mg, Zn, and Na.