Age-dependent decreases of phosphorus and magnesium in human achilles’ tendons

To elucidate changes of human tendons with aging, the authors studied age-related changes of elements in human Achilles’ tendons by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of seven men and seven women, ranging in age from 61 to 97 yr. It was found that the content of calcium increased progressively with aging in the Achilles’ tendons, whereas the contents of phosphorus and magnesium decreased gradually with aging. The previous investigations demonstrated that the content of calcium and phosphorus increased progressively with aging in most, but not all, human tissues, except for the bones. In ligaments, such as the anterior cruciate ligament and the ligament of the head of the femur, which are histologically similar to the Achilles’ tendon, it was previously found that both the contents of calcium and phosphorus increased with aging in the ligaments. It should be noted that the content of phosphorus in the Achilles’ tendons decreased during the aging process. In addition, it was found that there was a very high direct correlation between phosphorus and magnesium contents in the tendons, but not between calcium and phosphorus contents.     

Increases of calcium and magnesium and decreases of phosphorus and iron with aging in human uterine tubes

To elucidate compositional changes of the uterine tube by aging, the authors studied age-related changes of elements in human uterine tubes by inductively coupled plasma-atomic emission spectrometry. The uterine tubes were resected postmortem or surgically removed from patients with uterine myoma. It was found that the contents of calcium and magnesium increased progressively with aging in uterine tubes, whereas the contents of phosphorus and iron decreased gradually with aging. The sulfur content of uterine tubes remained constant and independent of aging. Regarding relationships between elements, significant relationships were found between calcium and magnesium contents, between phosphorus and iron contents, between phosphorus and sulfur contents, and between phosphorus and sodium contents in human uterine tubes.     

Increases of calcium and magnesium and decrease of iron in human posterior longitudinal ligaments of the cervical spine with aging

To elucidate compositional changes of ligaments with aging, the authors investigated age-related changes of elements in the posterior longitudinal ligaments (PLLs) by inductively coupled plasma—atomic emission spectrometry. After the ordinary dissection, PLLs were resected from the subjects ranging in age from 65 to 95 yr. The PLLs of the cervical spine were resected between the fourth and fifth cervical vertebrae, the PLLs of the thoracic spine between the fifth and seventh thoracic vertebrae, and the PLLs of the lumbar spine between the second and third lumbar vertebrae. Calcium and magnesium increased progressively with aging in the PLLs of the cervical spine, but they did not increase with aging in the PLLs of the thoracic and lumbar spine. In contrast, iron decreased gradually with aging in the PLLs of the cervical spine. Regarding the relationships among elements, significant correlations were found among the contents of calcium, phosphorus, magnesium, and sodium in the PLLs of the cervical spine.     

Age-related changes of element contents in the human meniscus

The relative contents (RCs) of elements in the human menisci from 23 subjects in the age range between 65 and 93 yr were analyzed by inductively coupled plasma atomic emission spectrometry. The RCs of sulfur, calcium, and phosphorus in menisci increased progressively until the 80s, being the highest in the 80s, and thereafter decreased. The RCs of magnesium in menisci increased progressively until the 90s. Regarding the medial and lateral menisci, higher RCs of magnesium and iron, and a lower RC of phosphorus were found in lateral menisci in comparison with those in medial menisci. There were sexual differences in the RCs of calcium and phosphorus of medial and lateral menisci. The RCs of calcium and phosphorus were about 50% higher in women’s menisci than in men’s. Histological examinations showed that structureless mucoid masses were observed in the menisci, with very high RCs of calcium and phosphorus being detected.     

Differences in Elements Between Intact and Disrupted Human Ligamenta Capitum Femorum

To compare the element compositions between intact (i.e., intact throughout its length) and disrupted (i.e., ligament no longer attached to the attachment) ligaments, the contents of elements in the human ligamenta capitum femorum (LCF) were analyzed by inductively coupled plasma-atomic emission spectrometry. Histological and immunohistological assessments were also performed in both groups. The subjects were 8 men and 32 women. Trace element analyses showed that the sulfur and iron contents were significantly greater in the intact group than in the disrupted group, while the phosphorus and magnesium contents were significantly smaller in the intact group than in the disrupted group. The calcium and zinc contents were smaller in the intact group than in the disrupted group, with no significant differences. Histologically, there were fibrocartilage cells and extracellular matrix metachromasia in ligaments of the intact group. In contrast, fibrocartilage cells disappeared, and fat cells appeared instead of collagen fibrils in ligaments of the disrupted group. The LCFs of the intact group were immunohistologically positive for all components examined including collagens, glycosaminoglycans, and proteoglycans. The increase in sulfur suggested the presence of high glycosaminoglycan levels associated with fibrocartilaginous metaplasia in the ligament by compressive force. The reduction in iron may show a decreased number of blood vessels in the synovium after ligament disruption. The increases in phosphorus, magnesium, and calcium are indicative of degenerative changes including calcification and ossification. We conclude that differences in the contents of elements between intact and disrupted LCFs indicate degenerative alterations to the ligament structure after disruption.     

Age-related changes of elements in the human articular disk of the temporomandibular joint

To elucidate compositional changes of the articular disk (AD) of the temporomandibular joint (TMJ) by aging, elements of the ADs resected from 18 cadavers were determined by inductively coupled plasma atomic-emission spectrometry. It was found that calcium contents of ADs in TMJs increased progressively with aging, whereas the sulfur contents of the ADs decreased slightly with aging. Regarding the content of phosphorus, the contents increased progressively with aging. The study revealed that age-related changes of calcium contents in the ADs of TMJs were similar to those in women’s pubic symphyses, but not those in intervertebral disks and menisci.     

Age-related changes of elements in human ureter

To elucidate changes of the ureter with aging, the authors investigated age-related changes of element contents in human ureters. The subjects consisted of seven men and seven women, ranging in age from 61 to 97 yr. The contents of calcium, sulfur, and iron in the ureters increased progressively with aging, whereas the contents of phosphorus and magnesium did not increase with aging. Significant relationships were found both between calcium and sulfur contents and between calcium and iron contents in the ureters, but not between calcium and either phosphorus or magnesium contents. It was noteworthy that a significant relationship was also found between sulfur and iron contents in the ureters. It remains uncertain whether calcium forms a compound with sulfur or iron in aged human ureters or not.     

Age-dependent increases of calcium and phosphorus in human epiglottal cartilage

To elucidate compositional changes of the elastic cartilage with aging, the authors investigated age-related changes of elements in the epiglottal cartilages by inductively coupled plasma-atomic emission spectrometry. After the ordinary dissection by medical students at Chiang Mai University was finished, the epiglottises were resected from the subjects. The epiglottal cartilages were isolated and the element contents were determined. The subjects consisted of 11 men and 14 women, ranging in age from 39 to 92 yr old. It was found that although the extent of accumulation of calcium and phosphorus was slight, calcium and phosphorus increased progressively in the epiglottal cartilages with aging. In contrast, sulfur, magnesium, zinc, iron and sodium did not change significantly in them. Regarding the relationships among elements, it was found that there were significant correlations among calcium, phosphorus, magnesium, and sodium in the epiglottal cartilages, with one exception between calcium and sodium contents. In comparison between men and women, no significant differences were found in the predominant elements such as calcium, sulfur, and phosphorus in the epiglottal cartilages.     

Age-related changes of elements in human thoracic ducts and azygos veins and relationships among elements

To elucidate compositional changes of the thoracic duct with aging, the authors investigated age-related changes of elements in the thoracic ducts in comparison with the azygos veins. The subjects consisted of 22 men and 1 woman, ranging in age from 65 to 95 yr. After ordinary dissection, the thoracic ducts and azygos veins were resected from the subjects and element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that calcium appeared to increase in the thoracic duct with aging, but the other elements, such as phosphorus, sulfur, magnesium, iron, zinc, and sodium, did not change significantly with aging. In the azygos vein, both calcium and sulfur increased significantly with aging. Regarding the relationship among elements, extremely significant direct correlations were found among calcium, phosphorus, sulfur, and magnesium in the thoracic ducts, except for phosphorus and magnesium contents with a very significant direct correlation. In the azygos veins, significant direct correlations were found between calcium and sulfur contents and between sulfur and magnesium contents. However, no significant correlations were found among calcium, phosphorus, and magnesium in the azygos veins. These results revealed that with regard to the relationship among calcium, phosphorus, and magnesium, the thoracic duct was similar to the arteries, but not to the azygos vein.     

Age-related variations of elements as compared among optic, radial, and sciatic nerves

To elucidate changes of peripheral nerves with aging, the authors studied age-related changes of element contents in the optic, radial, and sciatic nerves by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of seven men and seven women, ranging in age from 61 to 97 yr. The contents of phosphorus and sulfur remained constant through ages 61 to 97 yr in three nerves, the optic, radial, and sciatic nerves. It was found that there were age-related differences in calcium content among the optic, radial, and sciatic nerves: The calcium content of the optic nerve increased progressively with aging; in the radial nerve, it was hardly changed with aging; in contrast, the calcium content of the sciatic nerve decreased gradually with aging. In addition, it was found that in the radial nerve there were moderate correlations between age and zinc or sodium content, whereas significant correlations between age and the content of silicon or iron were found in the sciatic nerve. Furthermore, there was a correlation between the silicon and iron contents in the sciatic nerves.     

Relationships among element contents in the medial meniscus

To elucidate compositional changes of elements in the meniscus with aging, the authors investigated the relationships among elements in the medial meniscus by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 16 men and 7 women, ranging in age from 65 to 93 yr. In the left medial meniscus, extremely significant correlations were found both between calcium and phosphorus contents and between sulfur and magnesium contents, whereas significant correlations were found between calcium and either iron or zinc contents, between phosphorus and either iron or zinc contents, and between iron and zinc contents. On the other hand, in the right medial meniscus, there were only an extremely significant correlation between calcium and phosphorus contents and a significant correlation between sulfur and magnesium contents. The common finding between the left and right medial menisci was an extremely significant correlation between calcium and phosphorus contents and a significant correlation between sulfur and magnesium contents.     

High accumulations of calcium and phosphorus in women’s pubic symphysis

To elucidate compositional changes of the pubic symphysis (PS) by aging, elements of pubic symphyses (PSs) removed from 26 cadavers were determined by inductively coupled plasma atomic-emission spectrometry. It was found that the relative contents (RCs) of calcium and phosphorus in women’s PSs were about three-and five-fold amounts as compared with those in men’s PSs, respectively. In contrast, the RCs of sulfur, magnesium, sodium, and iron in women’s PSs were somewhat lower than those in men’s PSs. The accumulations of calcium (Ca) and phosphorus (P) in women’s PSs occurred mainly beyond the age of 70-yr-old, but did not occur in men’s PSs.     

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.     

Relationships among element contents in the internal jugular vein similar to the arteries

To elucidate compositional changes of the veins with aging, the authors investigated the relationships among element contents in the internal jugular veins, in which a higher accumulation of calcium and phosphorus occurred with aging. The subjects consisted of 15 men and 10 women, ranging in age from 40 to 98 yr. The element contents of the internal jugular veins were determined by inductively coupled plasma-atomic emission spectrometry. It was found that there were extremely significant direct correlations among the contents of calcium, phosphorus, magnesium, and sodium in the internal jugular vein. In addition, very significant direct correlations were also found both between zinc and either iron or silicon contents and between sulfur and iron contents in the vein. As calcium and phosphorus increased in the internal jugular vein, the mass ratios of Mg/Ca and Mg/P decreased gradually in the vein, whereas the mass ratio of Ca/P hardly decreased. These results indicated that with regard to both the relationships among the contents of calcium, phosphorus, and magnesium and the changes of the mass ratios of Mg/Ca and Mg/P, the internal jugular vein was very similar to the arteries.     

Age-dependent changes of elements in human trachea

To elucidate compositional changes of human trachea by aging, element contents in tracheae were determined by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of seven men and seven women, ranging in age from 61 to 97 yr. The sulfur content of the tracheae decreased gradually with aging. In regard to calcium and phosphorus, both the contents increased to about three-fold amounts in their seventies compared with those in their sixties, and decreased thereafter. The contents of calcium and phosphorus were the highest in their seventies. Therefore, it is likely that surplus calcium released from bones is deposited temporally in the trachea, and the deposits are released from the trachea at older age. Based on our results of human cartilages, there are two types in regard to calcium accumulation: The first type is that calcium accumulation occurs progressively with aging; the second one is that calcium accumulation becomes the highest in the seventies or eighties, and decreases there-after. Therefore, the trachea belongs to the second type. Furthermore, the magnesium content remained constant through the age range.     

Compositional changes of the muscular layers of the stomach with aging

To elucidate compositional changes of the stomach with aging, the authors investigated age-related changes of the elements and relationships among the elements in the muscular layers of the pylorus, cardia, lesser curvature, and greater curvature by inductively coupled plasma-atomic emission spectrometry. After ordinary dissection by medical students, the pylori, cardias, lesser curvatures, and greater curvatures were removed from the subjects, consisting of 19 men and 1 woman, ranging in age from 65 to 95 yr. The muscular layers were isolated and the element contents were determined.The calcium content increased progressively with aging in the muscular layers of the pylorus, cardia, and lesser curvature, whereas it tended to increase in the muscular layer of the greater curvature with aging. Regarding sulfur, the content increased significantly in the muscular layer of the pylorus with aging, but not significantly in the muscular layers of the cardia, lesser curvature, and greater curvature with aging.Regarding the relationships among the elements, significant direct correlations were found among calcium, phosphorus, sulfur, and magnesium in both the muscular layers of the pylori and cardias, with some exceptions.     

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.     

Age-related change of mineral content in the human thoracic aorta and in the human cerebral artery

The relative contents (RCs) of mineral elements in aortae and cerebral arteries from 23 subjects, with ages ranging between 45 and 99 yr, were analyzed by inductively coupled plasma atomic emission spectrometry. The RCs of calcium, phosphorus, and magnesium in the aortae increased markedly after the age of 70. While the RC of sulfur in aortae decreased gradually after that age. It was found that accumulation of calcium and phosphorus occurred primarily in the tunica media of aorta, and secondarily in the tunica intima. Furthermore, the RCs of calcium, phosphorus, and magnesium in cerebral arteries increased markedly after the age of 70, whereas the RC of sulfur in cerebral arteries decreased after age 70. It was found that accumulation of calcium and phosphorus in the cerebral arteries were 30 and 60%, respectively, lower than those in the aortae with ages ranging between 45 and 99 yr.     

Age-Related Decrease of the Phosphorus Content in the Ligamentum Capitis Femoris of Monkeys

To elucidate compositional changes of the ligament with aging, the authors investigated age-related changes of elements in the ligamentum capitis femoris (LCF) of monkeys with a wide range of ages by direct chemical analysis. Used rhesus and Japanese monkeys consisted of 9 males and 22 females, ranging in age from newborn to 31 years (average age?=?10.4?±?10.9 years). After incineration with nitric acid and perchloric acid, element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that the P content decreased significantly in the LCFs of monkeys with aging, but other six element contents, Ca, S, Mg, Zn, Fe, and Na, did not change significantly with aging. Assuming that the P content indicated the active cell density and the S content indicated the protein amount, an age-related change of the mass ratio of P/S was examined in the LCFs. The mass ratio of P/S decreased significantly in the LCFs in childhood. Regarding the relationships among elements, significant direct correlations were found among the Ca, P, S, and Mg contents in the LCFs. It was suggested that the active cell density of the connective tissue cells might decrease significantly in the LCF in childhood.     

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.