Mass ratios of magnesium to calcium and phosphorus in the arteries of Japanese and Thai

To elucidate quantitative changes of Ca, P, and Mg in the arteries with aging, the authors investigated changes of the mass ratios of Mg to Ca and P in the arteries of Japanese and Thai by inductively coupled plasma-atomic emission spectrometry. The arteries of Japanese that were used were the thoracic and abdominal aortas, coronary, common iliac, internal iliac, external iliac, and femoral arteries, in which very high accumulations of Ca and P occurred in old age. The arteries of Thai that were used were the abdominal aorta, ramifying site of the abdominal aorta, coronary, common iliac, internal iliac, and external iliac arteries. It was found that there were extremely significant correlations both between Ca and Mg contents and between P and Mg contents in all of the arteries of the Japanese and the Thai. With regard to the mass ratio, the mass ratios of Mg to Ca ranged from 1.5% to 2.1% in the six arteries of the Japanese, except for the thoracic aorta at 3.1%, at an advanced stage of atherosclerosis, being similar to each other. In the arteries of the Thai, the mass ratios of Mg to Ca ranged from 1.9% to 3.0%, except for the coronary artery at 0.5%, at an advanced stage of atherosclerosis. The mass ratios of Mg to P ranged from 2.5% to 2.7% in the six arteries of the Japanese, except for the coronary artery at 1.8%, at an advanced stage of atherosclerosis. With regard to the arteries of the Thai, the mass ratios of Mg to P ranged from 1.9% to 3.3%, except for the coronary artery at 0.7%, at an advanced stage of atherosclerosis. These results revealed that both the mass ratios of Mg to Ca and Mg to P were almost similar among the arteries of Japanese and Thai, except for the coronary arteries. Therefore, these results suggested that the inorganic deposits in the coronary arteries of Japanese and Thai were similar to those in the intimal tunica of the thoracic aorta, whereas in the other arteries, they were similar to those in the middle tunica of the thoracic aorta.     

High Accumulation of Calcium and Phosphorus in the Pineal Bodies with Aging

To elucidate compositional changes of the pineal body with aging, the authors investigated age-related changes of elements in the pineal body. After the ordinary dissection by medical students was finished, the pineal bodies and seven arteries were resected from the subjects ranging in age from 58 to 94 years. The element contents were determined by inductively coupled plasma atomic emission spectrometry. It was found that a high accumulation of Ca and P occurred in the pineal bodies with aging. Regarding the relationships among the elements, it was found that there were significant direct correlations among the contents of Ca, P, and Mg. With regard to the relationships between the pineal body and the arteries, no significant correlations were found in the Ca content between the pineal body and the arteries, such as the thoracic and abdominal aortas and the coronary, common carotid, pulmonary, splenic, and common iliac arteries.     

Accumulation of elements in the arteries and cardiac valves of Thai with aging

To elucidate whether the extent of element accumulation in the arteries and cardiac valves with aging was different between different races, the authors investigated the accumulation of elements in the arteries and cardiac valves of the Thai with aging and the relationships among elements in the cardiac valves. After ordinary dissection at Chiang Mai University was finished, 16 arteries and 4 cardiac valves were resected and element contents were determined by inductively coupled plasma-atomic emission spectrometry. In the 16 arteries, the average content of calcium was the highest in the site of the abdominal aorta ramifying into the common iliac arteries, and it decreased in the order internal iliac, coronary, abdominal aorta, common iliac, external iliac, superior mesenteric, inferior mesenteric, thoracic aorta, brachial, radial, common carotid, subclavian, ulnar, axillary, renal, and internal thoracic arteries. The average contents of phosphorus and magnesium in respective arteries were parallel with the average contents of calcium, except for the coronary artery. In comparison with the arteries of the Japanese, the trend of calcium accumulation in the arteries of the Thai was almost similar to that in the arteries of the Japanese, except for the coronary artery and thoracic aorta. The calcium accumulation in the coronary artery was much higher in the Thai than in the Japanese, whereas that in the thoracic aorta was lower in the Thai than in the Japanese. Regarding elements in the cardiac valves, the calcium content increased remarkably in the seventies in the aortic valve and in the nineties in the pulmonary valve, but it hardly increased in both the mitral and tricuspid valves with aging. The average content of calcium was the highest in the aortic valve, and it decreased in the order pulmonary, tricuspid, and mitral valves. Regarding the relationship among elements in the aortic valves, it was found that there were extremely significant direct correlations among the contents of calcium, phosphorus, and magnesium, whereas there were significant direct correlations between zinc and either calcium or phosphorus contents. Although significant correlations were found between sulfur and the other element contents in the aortic valves of the Japanese, no significant correlations were found between them in the aortic valves of the Thai. In the mitral valves, extremely or very significant direct correlations were found among the contents of calcium, phosphorus, magnesium, and sulfur, with some exceptions that there were no significant correlations between phosphorus and either magnesium or sulfur contents. In addition, no significant correlation was found in the calcium content between the aortic valve and coronary artery in the same individuals.     

Accumulation of calcium and phosphorus accompanied by inevitable accumulation of magnesium in human arteries

To examine whether there were differences between races in regard to the relationships among element contents in the arteries, the authors investigated the relationships among the average contents of calcium, phosphorus, sulfur, and magnesium in the 18 kinds of the Thai artery. After ordinary dissection by medical students at Chiang Mai University was finished, the thoracic and abdominal aortas, ramifying site of the abdominal aorta into the common iliac arteries, coronary, common carotid, internal thoracic, subclavian, axillary, brachial, radial, superior and inferior mesenteric, renal, common iliac, internal iliac, and external iliac arteries were resected from the subjects who consisted of 12 men and 3 women, ranging in age from 39 to 84 yr. The femoral and posterior tibial arteries were resected from the subjects, consisting of 15 men and 5 women, ranging in age from 25 to 88 yr. The element content of the arteries was analyzed by inductively coupled plasma-atomic emission spectrometry. It was found that there were extremely significant direct correlations among the average contents of calcium, phosphorus, and magnesium in the 18 kinds of the Thai artery, but no significant correlations were found between the average contents of sulfur and elements, such as calcium, phosphorus, and magnesium. These results were in agreement with those of the Japanese arteries. Therefore, it was suggested that there was no significant difference between the arteries of the Thai and the Japanese in the relationships among calcium, phosphorus, sulfur, and magnesium.     

Simultaneous accumulation of magnesium with calcium and phosphorus in aorta and iliac arteries of thai

To elucidate compositional changes of arteries with aging, the authors previously investigated age-related changes of mineral contents in the various arteries of Japanese and Japanese monkey. To examine whether there were differences between races in regard to age-related changes of mineral contents and the relationships among element contents in the arteries, the authors investigated the arteries of Thai. The subjects consisted of 13 men and 3 women, ranging in age from 39 to 84 yr. After the ordinary dissection at Chiang Mai University was finished, abdominal aortas, common iliac, internal iliac, and external iliac arteries were resected and the element contents were determined by inductively coupled plasma-atomic emission spectrometry. The contents of calcium, phosphorus, and magnesium became the highest in the fifties in the abdominal aorta, common iliac, and external iliac arteries, whereas the contents of calcium and magnesium became the highest in the sixties in the internal iliac artery, and decreased thereafter. In regard to relationships among element contents, it was found that there were high correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium in all of the abdominal aortas and three iliac arteries. The mass ratios of magnesium to calcium and phosphorus were each similar in the abdominal aorta, common iliac, and internal iliac arteries, except for the external iliac artery, in which it was slightly high. These revealed that as calcium and phosphorus increased in the arteries with aging, magnesium increased in the arteries as well. The differences between the arteries of Thai and Japanese were discussed in the present article.     

Accumulation of calcium in the arteries of Japanese monkey

To examine whether the calcium accumulation in the arteries is related to the way of walk or not, the calcium contents were determined in various arteries of Japanese monkeys of quadrupedal walk by inductively coupled plasma-atomic emission spectrometry. Japanese monkeys consisted of five males and four females, ranging in age from 2 to 29 yr. Age-related changes of the calcium content were examined in various monkey arteries. Significant relationships between age and calcium content were found in the arteries, such as the axillary, brachial, radial, subclavian, common carotid, common iliac, and femoral arteries, but not statistically in the thoracic and abdominal aortas, ulnar, external iliac, internal iliac, popliteal, and tibial arteries. The average contents of calcium were compared between the two groups of the monkeys below 14 yr and over 24 yr of age. Below 14 yr, the calcium content was a little higher in the arteries, such as the common, external and internal iliac, and femoral arteries than that of the other ones. Over 24 yr, the calcium content increased remarkably in the arteries, such as the thoracic aorta, common, internal and external iliac, common carotid, and subclavian arteries. The calcium contents of the thoracic aorta, common, internal and external iliac, common carotid, and subclavian arteries increased by more than two times over 24 yr compared with those below 14 yr. In a comparison between the calcium contents of the arteries in the anatomically corresponding regions of the upper and lower limbs, no statistically significant differences were found in the subjects over 24 yr as well as the subjects 2–29 yr of age. The calcium accumulation in the arteries of monkeys with aging was different from those in the arteries of humans, because in the case of human, a very high accumulation of calcium occurred in the arteries of the lower limb with aging in comparison with those in the upper limbs. Therefore, it is likely that different ways of walk or different species are partly affected in the calcium accumulation in the arteries with aging.     

Selective accumulations of aluminum in five human arteries

The aim of the present study was to determine variability of aluminum (Al) accumulation in human arteries and to observe the relationship between Al and five other elements (Ca, Fe, Mg, P, and Si) in the arteries. The Al contents in the thoracic aorta, basilar, coronary, femoral, and radial arteries of 26 human subjects were estimated by an inductively coupled plasma-atomic emission spectrometer and compared quantitatively to five elements. Al was detected in 88% of the cases in both the femoral and radial arteries, 73% in the coronary artery, 58% in the aorta, and 31% in the basilar artery. The average Al content was highest in the femoral artery (48.3 ± 15.0 μg/g dry weight) and lowest in the basilar artery (8.1 ± 3.6 μg/g). The Al had positive correlations with P, Ca, or Mg in both the aorta and femoral artery, and with Ca or P in the basilar artery. In the coronary artery, a correlation was found between Al and Si. No relationships were found between Al and each of the five elements in the radial artery. From these results, Al varied widely among the five arteries and accumulated more in the femoral and radial arteries but less in the basilar artery. These accumulations of Al were positively correlated with Ca or P in several arteries, but not sufficiently to explain the accumulation of Al. Further investigations are required to understand the mechanism of the variability of Al accumulation in the arteries.     

Accumulation of calcium and phosphorus accompanied by increase of magnesium and decrease of sulfur in human arteries

To elucidate the accumulation of elements in the arteries with aging, the authors investigated age-related changes of elements in human arteries, such as the thoracic aorta, femoral, basilar, coronary, radial, and common iliac arteries by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 17 men and 9 women, ranging in age from 55 to 92 yr in the cases of the five arteries, except for the common iliac arteries, in which the subjects consisted of 16 men and 8 women, ranging in age from 65 to 93 yr. It was found that there were significantly direct correlations between calcium and phosphorus contents and between calcium and magnesium contents in all of the six arteries: thoracic aorta, femoral, basilar, coronary, radial, and common iliac arteries. Significantly direct correlations were also found between phosphorus and magnesium contents in the five arteries, except for the basilar artery. In contrast, significantly inverse correlations were found between calcium and sulfur contents and between phosphorus and sulfur contents in the four arteries, except for the coronary and radial arteries. These revealed that the accumulation of calcium and phosphorus in the arteries was accompanied by an increase of magnesium in the arteries and by a decrease of sulfur in the arteries.     

Simultaneous accumulation of calcium, phosphorus, and magnesium in various human arteries

To elucidate compositional changes of the arteries with aging, the authors investigated the relationships among average contents of calcium, phosphorus, sulfur, and magnesium in the arteries by inductively coupled plasma-atomic emission spectrometry. The arteries used were the thoracic and abdominal aortas, coronary, common carotid, anterior, middle and posterior cerebral, vertebral, basilar, internal thoracic, axillary, radial, truncus celiacus, common, internal and external iliac, femoral, popliteal, and umbilical arteries. It was found that high correlations were found between the average contents of calcium and phosphorus, between the average contents of calcium and magnesium, and between the average contents of phosphorus and magnesium in the arteries, but not between the average contents of sulfur and the other elements. These correlations revealed that as the content of calcium and phosphorus increased in the arteries, the magnesium content increased simultaneously in the arteries, but the sulfur content did not. It is likely that magnesium forms compounds with phosphorus in the arteries.     

Earlier accumulation of calcium, phosphorus, and magnesium in the coronary artery in comparison with the ascending aorta, aortic valve, and mitral valve

To explore reasons for a high accumulation of Ca and P occurring in the coronary artery of Thai with aging, the authors investigated age-related changes of elements in the coronary artery, ascending aorta near the heart, and cardiac valves in single individuals, and the relationships in the elements between the coronary artery and either the ascending aorta or cardiac valves. After an ordinary dissection by medical students at Chiang Mai University was finished, the anterior descending arteries of the left coronary artery, ascending aortas, mitral valves, and aortic valves were resected from the subjects. The subjects consisted of 17 men and 9 women, ranging in age from 46 to 76 yr. The element content was analyzed by inductively coupled plasma-atomic emission spectrometry. The average content of Ca and P was the highest in the coronary artery and decreased in the order aortic valve, ascending aorta, and mitral valve. The Ca, P, and Mg content increased in the coronary artery in the fifties and in the ascending aorta, aortic valve, and mitral valve in the sixties. It should be noted that the accumulation of Ca, P, and Mg occurred earlier in the coronary artery than in the ascending aorta, aortic valve, and mitral valve. It was found that with respect to the Ca, P, Mg, and Na contents, the coronary artery correlated well with both the aortic valve and ascending aorta, especially with the aortic valve, but it did not correlate with the mitral valves. This finding suggests that the accumulation of Ca, P, Mg, and Na occurs in the coronary artery together with the aortic valve and ascending aorta, but not together with the mitral valve. Because regarding the accumulation of Ca, P, and Mg, the ascending aorta and aortic valve are preceded by the coronary artery, it is unlikely that the accumulation of Ca, P, and Mg spreads from the ascending aorta or aortic valve to the coronary artery.     

Increases of calcium and phosphorus in the uterine arteries with aging

To elucidate compositional changes of the uterine artery with aging, the authors investigated age-related changes of elements in the uterine arteries. After ordinary dissection by medical students at Nara Medical University was finished, the uterine arteries were resected from the subjects. The element content of the uterine arteries was analyzed by inductively coupled plasma-atomic emission spectrometry. The subjects ranged in age from 58 to 99 yr (average age=82.7±10.1 yr). It was found that the Ca, P, and Na contents increased progressively in the uterine arteries with aging. A significant accumulation of Ca and P in the uterine arteries was found in the sixties and increased markedly in the eighties. It should be noted that as far as the arteries in those over 70 yr of age, the extent of accumulation of Ca and P was the highest in the uterine arteries within the limits of the arteries analyzed by us. Regarding the relationships among elements, significant direct correlations were found among the contents of Ca, P, Mg, Zn, and Na. As Ca increased in the uterine arteries, P, Mg, Zn, and Na increased simultaneously in the arteries.     

Moderate Accumulation of Calcium and Phosphorus in the Splenic Artery with Aging and Low Accumulation of Those in the Pulmonary Artery with Aging

To elucidate compositional changes of the arteries with aging, the authors investigated age-related changes of elements in the splenic and pulmonary arteries, which supplied blood to contractile organs. After ordinary dissection by medical students at Nara Medical University was finished, the splenic and pulmonary arteries were resected from the subjects, ranging in age from 58 to 94 years. The element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that a moderate accumulation of Ca and P occurred in the splenic artery with aging, but it hardly occurred in the pulmonary artery with aging. Regarding the relationship among elements, the finding that there were significant direct correlations among the contents of Ca, P, Mg, and Na was commonly obtained in both the splenic and pulmonary arteries. The accumulation of Ca and P in the splenic artery with aging occurred independently of that in the pulmonary artery. Histologic observation indicated that a major part of Ca deposits was seen in the middle tunica, but not in the internal tunica. Therefore, the calcification occurring in the splenic artery belonged to middle sclerosis.     

Accumulation of magnesium as well as calcium and phosphorus in Japanese monkey arteries with aging

To examine whether an accumulation of elements in the arteries with aging differs between human and animal, the authors investigated the relationships among element contents in the arteries of the Japanese monkeys. The Japanese monkeys consisted of five males and four females, ranging in age from 2 to 29 yr. The aorta, common and external iliac, femoral, common carotid, subclavian, and axillary arteries were resected from the monkeys and element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that there were very high correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium contents in all of the monkey arteries. In addition, significant correlations were found among the other element contents in some, but not all of the arteries. These results were consistent with the foregoing findings of the human arteries. It is likely that magnesium forms compounds with phosphorus or calcium in the monkey arteries.     

Age-dependent Increases of Calcium, Phosphorus, and Sodium in the Uterine Arteries of Thai

To elucidate compositional changes of the uterine artery with aging, the authors investigated age-related changes of elements in the uterine arteries of Thai. After ordinary dissection by medical students at Chiang Mai University was finished, the uterine arteries were resected from Thai subjects. Thai subjects ranged in age from 27 to 86 years (average age = 63.3 +/- 17.7 years). The element content of the uterine arteries was analyzed by inductively coupled plasma-atomic emission spectrometry. It was found that the Ca, P, and Na contents increased progressively in the uterine arteries of Thai with aging. A significant accumulation of Ca and P in the uterine arteries of Thai was found in the sixties patients, and the accumulation increased markedly in the seventies. Regarding the uterine arteries in subjects more than 60 years, the extent of accumulation of Ca and P in the uterine arteries of Thai was one half of that in the uterine arteries of Japanese. Regarding the relationships among elements, extremely significant direct correlations were found among the contents of Ca, P, Mg, Zn, and Na in the uterine arteries of Thai. As Ca increased in the uterine arteries of Thai, P, Mg, Zn, and Na increased simultaneously in the arteries.     

Quantitative changes of calcium, phosphorus, and magnesium in common iliac arteries with aging

To elucidate the mechanism of element accumulations in the arteries with aging, the authors investigated the mass ratios among calcium, phosphorus, and magnesium in the common iliac arteries by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 16 men and 8 women, ranging in age from 65 to 93 yr. It was found that there were extremely significant correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium contents in the common iliac arteries. In regard to the mass ratio, although the mass ratio of calcium to phosphorus was almost constant, the mass ratios of magnesium to calcium and phosphorus were different at early and advanced stages of the accumulation of calcium and phosphorus. It was found that both the mass ratios of magnesium to calcium and phosphorus were higher at an early stage of the accumulation of calcium and phosphorus in the arteries than at an advanced stage of the accumulation.     

Compositional changes of the aortic valve similar to the artery with aging

To elucidate compositional changes of the cardiac valves with aging, the authors investigated the relationships among element contents in the aortic valves, in which the accumulation of calcium and phosphorus was the highest. The subjects consisted of 10 men and 14 women, ranging in age from 65 to 102 yr. Extremely significant direct correlations were found among the contents of calcium, phosphorus, magnesium, sodium, and zinc in the aortic valves. In contrast, significant inverse correlations were found between the contents of sulfur and the other elements, such as calcium, phosphorus, magnesium, and sodium. It should be noted that these correlations present in the aortic valves were very similar to those in the arteries, especially those in the thoracic aortas. The changes of the mass ratios of Mg/Ca and Mg/P in the aortic valves were similar to those in the thoracic aortas. As calcium and phosphorus increased in the aortic valve, the mass ratios Mg/Ca and Mg/P decreased reversely in the aortic valve. These results suggest that the compositional change of the aortic valve is very similar to that of the thoracic aorta.     

Correlations of calcium accumulations in arteries, veins, cartilages, ligaments, and bones in single humans

To show the relationships of calcium accumulation in the thoracic aorta to the other tissues, calcium contents were determined with a microwave-induced plasma-atomic emission spectrometer on arteries, veins, cartilages, ligaments, and bones. These tissues were resected from 18 individuals, consisting of 11 men and 7 women who died in the age range 59–91 yr. As thoracic and abdominal aortas are routinely used for radiographic examination of arterial calcification, they appear to be standard tissues of the calcium accumulation. The calcium accumulations were determined in the femoral artery, the superior and inferior venae cavae, the internal jugular vein, cartilages of the articular disk of the temporomandibular joint and the intervertebral disk, both the ligaments of the anterior cruciate ligament and the ligamentum capitis femoris, and the calcaneus, in contrast with the thoracic aorta. As calcium increased in the thoracic aorta, it increased in the femoral artery, the articular disk of the temporomandibular joint, the intervertebral disk, both ligaments of the anterior cruciate ligament, and the ligamentum capitis femoris, but it did not increase in veins, such as the superior and inferior venae cavae and the internal jugular vein. In contrast, it decreased in the calcaneus.     

Accumulation of calcium in human common iliac artery, aortic valve, xiphoid process, costal cartilage, posterior longitudinal ligament, trigeminal nerve, and rib accompanied by increase of magnesium

To examine whether an accumulation of Ca in the tissues was accompanied by an increase of Mg, the authros investigated the relationships between Ca and Mg contents in the common iliac arteries, aortic valves, xiphoid processes, costal cartilages, posterior longitudinal ligaments, trigeminal nerves, and ribs by inductively coupled plasma-atomic emission spectrometry. After the ordinary dissections by medical students were finished, the common iliac arteries, aortic valves, xiphoid processes, bilateral the fourth costal cartilages, posterior longitudinal ligaments between the fourth and fifth cervical vertebrae, trigeminal nerves, and bilateral the sixth ribs were resected from the subjects and elements were determined. It was found that there were extremely significant direct correlations between Ca and Mg contents in all of the common iliac arteries, aortic valves, costal cartilages, posterior longitudinal ligaments, and trigeminal nerves, whereas there were significant direct correlations in both the xiphoid processes and ribs. As for the tissues containing Ca higher than 20 mg/g, the average mass ratios of Mg/Ca were similar among the seven tissues. As Ca increased in all of the common iliac arteries, aortic valves, xiphoid processes, costal cartilages, posterior longitudinal ligaments, trigeminal nerves, and ribs, Mg increased simultaneously in the seven tissues.     

Distribution of the vasoconstrictor and vasorelaxant effects of norbormide along the vascular tree of the rat

Norbormide is a vasoconstrictor of rat peripheral arteries and a relaxant in rat aorta. To characterise norbormide actions within the rat vascular tree we have investigated its effects on the contractile function of rings from several arteries and veins. A maximal norbormide concentration (50 microM) failed to contract thoracic aorta and carotid artery, whereas in pulmonary artery, abdominal aorta, iliac, caudal, and femoral arteries it induced a contractile effect that was respectively 4.8 +/- 0.6, 18.4 +/- 1.5, 39 +/- 5, 144 +/- 7, and 260 +/- 22% of that induced by 90 mM KCl. In pulmonary, carotid, and iliac arteries, and in thoracic and abdominal aorta, 50 microM norbormide inhibited KCl-induced responses. Norbormide (50 microM) contracted all veins investigated. The effect, expressed as % of KCl-induced contraction, was 121 +/- 25, 154 +/- 14.5, 154 +/- 18.2, 203 +/- 19, and 267 +/- 33 for pulmonary vein, thoracic and abdominal vena cava, iliac and jugular veins, respectively. In jugular vein, as previously shown in rat caudal artery, norbormide contraction was abolished in Ca2+-free medium, was unaffected by the Ca2+ channel blocker nifedipine, and was relaxed by SK&F 96365, a blocker of store-operated Ca2+ channels. In conclusion: i) rat veins represent the main target for contractile norbormide action; ii) in both artery and veins norbormide contractions are generally inversely related to the calibre of the vessel; iii) norbormide-induced contraction is mediated by the same mechanism/s in arteries and veins; iiii) in norbormide-contracted arteries the drug activates both contractile and relaxing mechanisms.     

Different accumulation of elements in the rami of the coronary arteries of Thai

To analyze the accumulation of elements in the rami of the coronary arteries, the authors determined element contents in both the coronary arteries and their rami of the Thai by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 13 men and 6 women, ranging in age from 34 to 83 yr. It was found that a higher accumulation of calcium and phosphorus occurred in the proximal sites of coronary arteries such as the anterior descending, right coronary, left coronary, and circumflex arteries than the distal sites such as the diagonal, lateral, conus, acute marginal, and posterior descending arteries. The accumulation of calcium and phosphorus in the anterior descending and right coronary arteries of the Thai increased remarkably in the fifties, thereafter decreased, and increased again in the eighties. It should be noted that a very high accumulation of calcium and phosphorus in the coronary arteries occurred in the fifties. In regard to relationships among the average contents of elements in the coronary arteries and their rami, it was found that there were very significant direct correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium contents. These results suggested that as calcium and phosphorus increased in the coronary arteries and their rami, magnesium increased simultaneously in all of the coronary arteries and their rami.