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.     

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.     

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 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.     

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.     

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.     

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.     

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.     

Temporal variability of particulate organic carbon,nitrogen and phosphorus in the Northern Adriatic Sea

The particulate organic carbon (POC), nitrogen (PN) and phosphorus (PP) vertical distribution along the water column and temporal variability in coastal and offshore waters of the Northern Adriatic Sea were related to the hydrodynamic conditions and biological processes. Fresh water inputs from the Po and Adige rivers enhance primary production, resulting in high POC, PN and PP concentrations at the surface. In offshore waters, POC and PN concentrations were about 3–4 times less than in the coastal waters, while PP were up to 10 times lower, highlighting a marked phosphorus depletion. In the bottom layer, the POC content decreases due to the strong density gradients which separate bottom waters with prevailing degradation processes. Short term 48 h-variability of POC, PN and PP in the coastal waters was determined to a great extent by variations in the spreading of river plumes at the surface and by nepheloid layers and resuspension processes in the bottom waters. The particulate matter in the Adriatic offshore waters is extremely depleted as regards particulate phosphorus and is characterised by C_org:P and N:P ratios higher than the Redfield ratio.     

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.     

High accumulation of calcium and phosphorus in the coronary artery of the Thai in comparison with the Japanese

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 coronary arteries of Thai and Japanese. The Thai subjects consisted of 13 men and 3 women, ranging in age from 39 to 84 yr, whereas the Japanese subjects consisted of 17 men and 9 women, ranging in age from 55 to 92 yr. After the ordinary dissections at Chiang Mai University and Nara Medical University were finished, the coronary arteries were resected and the element contents were determined by inductively coupled plasma-atomic emission spectrometry. In the Thai, an accumulation of calcium and phosphorus began to occur in the forties and increased markedly in the fifties, whereas in the Japanese, an accumulation of calcium and phosphorus began to occur in the seventies and increased markedly in the nineties. The result revealed that an accumulation of calcium and phosphorus occurred earlier in the Thai than in the Japanese. Regarding the relationships among element contents, extremely significant correlations were found between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium contents in both the coronary arteries of the Thai and the Japanese. As far as the coronary arteries with a very high accumulation of calcium and phosphorus, the mass ratios of magnesium to calcium and phosphorus were lower in the coronary arteries of the Thai in comparison with the Japanese.     

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.     

Dietary and physiological studies to investigate the relationship between calcium and magnesium signalling in the mammalian myocardium

This study employs both dietary and physiological studies to investigate the relationship between calcium (Ca²⁺) and magnesium (Mg²⁺) signalling in the mammalian myocardium. Rats maintained on a low Mg²⁺ diet (LMD; 39 mg Kg^-1 Mg²⁺ in food) consumed less food and grew more slowly than control rats fed on a control Mg²⁺ diet (CMD; 500 mg Kg^-1 Mg²⁺ in food). The Mg²⁺ contents of the heart and plasma were 85 ± 3% and 34 ± 6.5%, respectively relative to the control group. In contrast, Ca²⁺ contents in the heart and plasma were 177 ± 5% and 95 ± 3%. The levels of potassium (K⁺) was raised in the plasma (129 ± 16%) and slightly decreased in the heart (88 ± 6%) compared to CMD. Similarly, sodium (Na⁺) contents were slightly higher in the heart and lowered in the plasma of low Mg²⁺ diet rats compared to control Mg²⁺ diet rat. Perfusion of the isolated Langendorff's rat heart with a physiological salt solution containing low concentrations (0-0.6 mM) of extracellular magnesium [Mg²⁺]₀ resulted in a small transient increase in the amplitude of contraction compared to control [Mg²⁺]₀ (1.2 mM). In contrast, elevated [Mg²⁺]₀ (2-7.2 mM) caused a marked and progressive decrease in contractile force compared to control. In isolated ventricular myocytes the L-type Ca²⁺ current (I_Ca,L was significantly (p < 0.001) attenuated in cells dialysed with 7.1 mM Mg²⁺ compared to cells dialysed with 2.9 µM Mg²⁺. The results indicate that hypomagnesemia is associated with decrease levels of Mg²⁺ and elevated levels of Ca²⁺ in the heart and moreover, internal Mg²⁺ is able to modulate the Ca²⁺ current through the L-type Ca²⁺ channel which in turn may be involved with the regulation of contractile force in the heart.     

Phosphorus nutritional effects on root hydraulic conductance,xylem water flow and flux of magnesium and calcium in squash plants

Previous studies have found that P nutrition of plants is an important factor in the uptake and translocation of Mg and Ca, and increasing root osmotic hydraulic conductance (L_o) and osmotically driven xylem exudate flow (J_v). Experiments were designed to determine if the observed changes in Mg and Ca uptake and translocation, J_v, and L_o from altered P nutrition are related or are separate functions. When six-week old squash (Cucurbita pepo L.) plants grown in perlite were treated with P levels ranging from 50 to 400 μM P for seven days, J_v and L_o increased as P treatment level increased. Xylem exudate concentrations of Mg and Ca were maintained as J_v increased, resulting in an increase in total flux of these mineral elements. The increase in Mg and Ca flux in the xylem exudate correlated with increased shoot Mg and Ca levels as P nutritional level was raised. Further studies with greenhouse grown plants indicated that the increases in J_v, L_o, and Mg and Ca flux were more responsive to changes in P nutritional level than to similar changes in levels of other anions. In hydroponically grown squash plants, xylem exudate was collected for a 20 min period after 0, 2 and 4 h in treatments of 50 and 500 μM P or after P treatment was increased from 50 to 500 μM. Immediately after nutrient solution P was increased (time 0), there was a 33% increase in J_v and a 22% increase in L_o when compared to the 50 μM P treatment. The J_v and L_o of the 50–500 μM P treatment did not equal levels of the continuous 500 μM control at time 0, but were similar after 2 and 4 h. Flux of Mg and Ca did not increase as rapidly as J_v in the 50–500 treatment indicating that regulation of Mg and Ca uptake and xylem loading by P may lag behind that of water movement. This revised version was published online in June 2006 with corrections to the Cover Date.     

Age-dependent decreases of sulfur and magnesium in human round ligaments of the uterus and relationships among elements

To elucidate the compositional change of ligaments with aging, the authors investigated both age-related changes of elements and relationships among elements in the round ligaments of the uterus (round ligaments) by inductively coupled plasma-atomic emission spectrometry. The bilateral round ligaments were resected from 20 cadavers and also from the uteri removed surgically from 11 patients bearing uterine myoma or cancer. Thirty-one subjects ranged in age from 34 to 92 yr. It was found that both S and Mg decreased gradually in the round ligaments with aging, but Ca, P, Zn, Fe, and Al did not change significantly with aging. Regarding the relationships among elements, very significant direct correlations were found among the contents of Ca, P, S, and Mg in the round ligaments, whereas significant inverse correlations were found between the contents of Zn and elements, such as Ca, P, S, and Mg. It should be noted that there was an extremely significant direct correlation between Ca and P contents in the round ligaments.     

Effects of land use in the drainage area on phosphorus binding and mobility in the sediments of four drinking-water reservoirs

The study of four drinking-water reservoirsdemonstrates how the anthropogenic land use of acatchment may affect binding and mobility ofphosphorus in the sediment. P_diss concentrationgradients at the sediment–water interface weremeasured to calculate potential diffusive releaserates. P binding forms were determined by sequentialextraction of fresh sediment and settling seston. Mainstudy sites were Saidenbach Reservoir (mesotrophic,densely populated drainage area with 73% agriculturalland use) and Neunzehnhain Reservoir (oligotrophic,unpopulated drainage area forested to 80%) in thesilicate-rich Erzgebirge mountains of eastern Germany.Tot-P concentrations and P binding forms of typicalerosive matter from each catchment were similar to thesediment of both pre-reservoirs and reservoirs' mouth.In Saidenbach Reservoir, diatoms responded to highnutrient loading by incorporating ortho-P. Whilesettling, the org-P was partly transformed toFe(OOH)P. Apart from hypolimnetic O₂depletion, this P binding form dominated in thesurface sediment mainly in front of the dam. Withincreasing sediment depth, org-P and Fe(OOH)Pnot only redissolved into the pore water, but alsoadsorbed onto Al compounds. In Neunzehnhain Reservoir,acidification of the low buffered catchment favouredloading of humic compounds and Al³+ ions, whichprecipitated and redox-independently adsorbed ortho-Pdue to a pH increase in the lake. Neunzehnhainsediment was able to immobilize Fe(OOH)P fromSaidenbach sediment in a batch experiment. Comparativesequential P extraction of sediment from SosaReservoir (oligo-mesotrophic, sparsely populateddrainage area forested to 94%) and Kleine KinzigReservoir (nearly unpopulated drainage area forestedto 98%) also demonstrated effective P immobilizationby Al-/humic compounds.It is concluded that the absence of settlements in thecatchment, together with forestry as dominating landuse, favour not only oligotrophic conditions in thereservoir but also confine internal P loading from thesediment. But attention should be paid toacidification problems.     

The action of excessive,inorganic silicon (Si) on the mineral metabolism of calcium (Ca) and magnesium (Mg)

The influence of silicon treatment on the levels of calcium and magnesium in blood serum and tissues was studied in rats. The concentrations of both elements were estimated in samples of sera and tissues of rats receiving per os a soluble, inorganic silicon compound—sodium metasilicate nonahydrate (Na₂SiO₃·9H₂O (REACHIM, USSR)), dissolved in the animals' drinking water. A decrease of magnesium concentration in serum was observed with accompanying elevation of registered calcemia. Moreover, a reduction of tissue calcium levels was found with a simultaneous increase of magnesium tissue pool. The results provide evidence for silicon involvement in mineral metabolism. It could result in a modification of pathological processes concerning bone tissue.     

Influence of different dietary calcium levels on the digestibility of Ca,Mg, and P in captive‐born juvenile Galapagos giant tortoises (Geochelone nigra)

Calcium (Ca) and phosphorus (P) are very important minerals in reptile nutrition, but many diets still are not balanced. To achieve optimal growth, including a healthy skeleton and a strong shell, a well‐balanced supply with these minerals is prerequisite. The purpose of this study was to evaluate the digestibility of diets with different calcium levels, with special emphasis on the digestibility of minerals. Fourteen captive‐born juvenile Galapagos giant tortoises of the Zurich and Rotterdam Zoos were used. The animals were housed indoors at a mean temperature of 23°C and 25°C, and at 65% and 60% humidity, respectively. The animals from the same zoo were fed the same diet, which consisted of vegetables, herbs, and a mixture of different Ca sources. Daily mixed fecal samples of all tortoises were collected from day 8 to day 18. A Weender analysis was performed and the HCl‐insoluble ash was used as an indigestible indicator (marker) for the determination of the apparent digestibility. The Ca content of the mixed feedstuffs of diet I was 1.43% on a dry matter basis, and the Ca:P ratio in the food was 3.9:1. In diet II, the Ca content was 2.06% on a dry matter basis, and the Ca:P ratio in the food was 4.8:1. Diet III contained 7.33% of Ca on a dry matter basis, and the Ca:P ratio in the food was 6.7:1. The digestibility of Ca in diet I was 42%. The other examined minerals, Mg and P, had a digestibility of 54% and 84%, respectively. In diet II, the digestibility of Ca was 63%, of Mg 76%, and of P 88%, and in diet III the digestibility of Ca was 82%, of Mg 92%, and of P 91%. The results of this study indicated that higher Ca concentrations in the diet led to an increased apparent digestibility of Ca, Mg, and P. The influence of an increased fat and decreased fiber content in diet III concerning digestibility is discussed. Zoo Biol 20:367–374, 2001. © 2001 Wiley‐Liss, Inc.