Cho Azuma

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.

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.

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.

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.

Age-related changes of elements and relationships among elements in human tendons and ligaments

To elucidate compositional changes of the tendons and ligaments with aging, the authors investigated age-related changes of element contents in the insertion tendons of the biceps brachii muscle, central tendons of the diaphragma, Achilles’ tendons, posterior longitudinal ligaments (PLLs) of the cervical spine, ligamenta capitum femorum, and anterior cruciate ligaments. After ordinary dissections by medical students, the three tendons and three ligaments were resected and element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that the elements, such as Ca, P, S, Mg, Na, Zn, and Fe, did not change significantly in the three tendons and two ligaments with aging, except for the PLLs where Ca and Mg increased significantly with aging and Fe decreased significantly with aging.With regard to the relationships among elements, the common finding that there were significant correlations between Ca and P contents and between Ca and Mg contents was obtained in the three ligaments. Likewise, the common finding that there was a significant correlation between Ca and Mg contents was obtained in the three tendons. Regarding the relationship between Ca and P contents, the three tendons were different from the three ligaments.

Developmental Changes in Desensitisation of c‐Fos Expression Induced by Repeated Maternal Separation in Pre‐Weaned Mice

Early‐life stress has long‐lasting effects on neuroendocrine and behaviour in adulthood. Maternal separation (MS) is used as a model of early‐life stress and daily repeated MS (RMS) for 3 h during the first two postnatal weeks is widely used in rodent studies. However, it is not fully understood whether early‐life animals desensitise/habituate to repeated stress. In the present study, we investigated the effects of daily RMS for 3 h and acute/single time MS (SMS) for 3 h on the plasma corticosterone level and c‐Fos expression in the brain in mice at different postnatal ages. Mice were subjected to: (i) RMS from postnatal day (PND) 1 to 14 (RMS14); (ii) RMS from PND14 to 21 (RMS21); (iii) SMS on PND14 (SMS14); and (iv) SMS on PND21 (SMS21). Plasma corticosterone and c‐Fos expression were examined on the final day in each experiment. The basal corticosterone levels in RMS14 and RMS21 were equal to those in respective age‐matched controls. After the final separation, the levels were significantly increased and were comparable with those after SMS14 and SMS21, respectively. Histological analysis indicated that c‐Fos expression significantly increased in many brain regions, including the paraventricular nucleus, prefrontal cortex, hippocampus, and basolateral and medial amygdale in both SMS14 and SMS21 mice. However, c‐Fos expression in RMS14 mice significantly increased in many regions, whereas such increases were hardly seen in RMS21 mice. These results indicate that repeated early‐life stress neither increases basal corticosterone, nor decreases the magnitude of the corticosterone response during the first three postnatal weeks, although desensitisation of c‐Fos expression induced by repeated stress is changed during postnatal development.

Elements of calcified sites in human thoracic aorta

To elucidate the manner of element accumulation in the arteries with aging, the authors investigated the element contents in the calcified and surrounding sites of the thoracic aortas by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of three men and five women, ranging in age from 45 to 99 yr. The calcified, calcification-surrounding, and control (which appeared normal) sites were removed from the thoracic aortas and the element contents were determined. It was found that the contents of calcium, phosphorus, magnesium, zinc, and aluminum were higher in the calcified site than in the control site, whereas the contents of sulfur, iron, and lead were lower in the calcified site than in the control site. The contents of the elements in the surrounding site were intermediate between those of the calcified and control sites, except for the magnesium and lead contents, which were the lowest.The mass ratios of magnesium to calcium and phosphorus were lower in the calcified site compared with the surrounding and control sites, and as calcium and phosphorus increased in the aorta, the mass ratios lowered gradually in the aorta.

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.

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.

Relationships among element contents in the intimal, middle, and external tunicae of the thoracic aorta.

To examine an accumulation of elements within the arteries with aging, the authors investigated the element contents in the intimal, middle, and external tunicae of the thoracic aorta. The subjects consisted of six men and four women, ranging in age from 57 to 99 yr. The wall of the thoracic aorta was separated into the intimal, middle, and external tunicae by scrubbing the wall of the thoracic aorta with an edge of slide glass and the element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that there were significant relationships among calcium, phosphorus, magnesium, sulfur, and sodium in both the intimal and middle tunicae of the aorta, but not in the external tunica. These results revealed that no significant differences were found in element compositions of deposits between the intimal and middle tunicae.