Calcium,phosphorus, calcium-phosphorus ratio in rib bone of healthy humans

Calcium and phosphorus concentrations as well as the Ca/P ratio were estimated in intact rib bone samples from healthy humans, 37 women and 45 men, aged 15–55 yr. For Ca and P concentration measurements, instrumental neutron activation analysis was used. The mean values (mean±SD) for the investigated parameters were 19.3±4.5% of dry bone weight, 8.42±2.14% of dry bone weight, and a ratio of 2.33±0.34, respectively. Statistically significant differences for the above parameters were not observed to be related either to age or sex. The mean values for Ca, P, and the Ca/P ratio were within a very wide range of published data and close to their medians. The individual variation for the Ca/P ratio in rib bone from healthy humans was lower than those for Ca and P taken separately. An indication is that the specificity of the Ca/P ratio improves upon that for Ca and P concentrations and may be more reliable in the diagnosis of bone disorders.     

Scarce Occurrence of Calcification in Human Sinoatrial Nodal Arteries in Old Age

To elucidate age-related changes of the sinoatrial (sinuatrial) nodal (SAN) artery, the authors investigated age-related changes of elements in the SAN artery by direct chemical analysis. In addition, the effects of different arterial origins, arterial sizes, and genders on element accumulation were investigated in the SAN artery. Fifty-nine formalin-fixed adult Thai hearts were dissected, and the following three types of the SAN artery were found: The first type was a single SAN artery arising from the right coronary artery (RCA). The second type was a single SAN artery arising from the proximal segment of the left circumflex artery (LCX). The third type was dual SAN artery arising from both the RCA and the LCX. For element analysis, both 41 single SAN arteries arising from the RCA and the LCX and 18 larger branches of dual SAN artery were used. After the arteries were incinerated with nitric acid and perchloric acid, element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that seven element contents such as Ca, P, S, Mg, Zn, Fe, and Na did not change significantly in the SAN arteries with aging. Regarding the relationships among seven elements in the SAN arteries, extremely significant direct correlations were found among P, S, Mg, and Fe contents with one exception. However, no significant correlations were found between Ca and either P or Mg contents in the SAN arteries. To examine an effect of the different arterial origins on element accumulation, the SAN arteries were separated into the RCA and the LCX groups by the arterial origin and age-related changes of element contents were compared between two groups. It was found that there were no significant differences between the RCA and the LCX groups in age-related changes of Ca and P contents. No gender differences were found in age-related changes of Ca and P contents in the SAN arteries. To elucidate whether calcification occurred in the SAN arteries in old age, both the mass ratios of Ca/P and Mg/Ca were estimated in the SAN arteries. The mass ratio of Ca/P increased progressively in the SAN arteries with Ca increase, being not constant. The mass ratio of Mg/Ca decreased gradually in the SAN arteries with Ca increase, but the average mass ratio of Mg/Ca was very high, being 49.4 ± 16.5%. These results indicated that calcification scarcely occurred in the SAN arteries in old age, independently of the arterial origin and gender.     

Evaluation of the 3D spatial distribution of the Calcium/Phosphorus ratio in bone using computed-tomography dual-energy analysis

PurposeThe Calcium/Phosphorus (Ca/P) ratio was shown to vary between healthy bones and bones with osteoporotic symptoms. The relation of the Ca/P ratio to bone quality remains under investigation. To study this relation and determine if the ratio can be used to predict bone fractures, a non-invasive 3D imaging technique is required. The first aim of this study was to test the effectiveness of a computed-tomography dual-energy analysis (CT-DEA) technique developed to assess the Ca/P ratio in bone apatite (collagen-free bone) in identifying differences between healthy and inflammation-mediated osteoporotic (IMO) bones. The second aim was to extend the above technique for its application to a more complex structure, intact bone, that could potentially lead to clinical use.MethodsFor the first aim, healthy and IMO rabbit cortical bone apatite samples were assessed. For the second aim, some changes were made to the technique, which was applied to healthy and IMO intact bone samples.ResultsStatistically significant differences between healthy and IMO bone apatite were found for the bulk Ca/P ratio, low Ca/P ratio proportion and interconnected low Ca/P ratio proportion. For the intact bone samples, the bulk Ca/P ratio was found to be significantly different between healthy and IMO.ConclusionsResults show that the CT-DEA technique can be used to identify differences in the Ca/P ratio between healthy and osteoporotic, in both bone apatite and intact bone. With quantitative imaging becoming an increasingly important advancement in medical imaging, CT-DEA for bone decomposition could potentially have several applications.     

饲料钙磷含量和钙磷比对生长期大鼠体重增长与骨骼发育的影响

目的研究饲料中不同的钙磷含量和钙磷比对生长期实验大鼠体重及骨骼发育的影响。方法采用完全随机化设计方案,取1月龄（100±10）g清洁级Wistar雄性大鼠70只,随机分成7组,每组10只,饲喂7种不同钙磷含量的饲料。自由采食,饮用去离子水,试验期42 d。各组于实验开始和结束时称重。试验结束后,处死动物并分离一侧胫骨和股骨用于实验指标的检测。结果当保持饲料中钙或者磷中的一种含量不变的情况下,调整另一种的含量即改变钙磷比例时,1.2∶1的正常钙磷比例组生长期实验大鼠增重及骨骼发育要明显好于0.4∶1的低钙磷比例组和4∶1的高钙磷比例组（P〈0.05）,并且当保持饲料中钙磷比例不变时,即使在低钙低磷和高钙高磷进食水平下,正常钙磷比例组大鼠增重及骨骼发育都较好,但低钙磷比例组和高钙磷比例组大鼠增重及骨骼发育则由于饲料中钙磷含量的变化波动较大（P〈0.05）。结论饲料中钙和磷需按比例添加,如果两者绝对含量相差过大就会影响到动物的增重及骨骼发育,本实验证明饲料钙磷比为1.2∶1时生长期实验大鼠增重及骨骼发育较好。     

Reduction in Dietary Calcium/Phosphorus Ratio Reduces Bone Mass and Strength in Ovariectomized Rats Enhancing Bone Turnover

To clarify the effects of the dietary calcium (Ca)/phosphorus (P) ratio on bone mineralization under the condition of estrogen deficiency, Wistar strain female rats were ovariectomized (OVX) at 12 weeks old. At 16 weeks old, the rats were divided into three dietary groups fed varying levels of P containing 0.5% Ca: 0.25% P, Ca/P=2; 0.5% P, Ca/P=1; and 1.0% P, Ca/P=0.5 respectively. This study indicates that the reduction of the dietary Ca/P ratio impairs trabecular bone turnover accompanying the acceleration of bone formation in OVX rats.     

Reduction in dietary calcium/phosphorus ratio reduces bone mass and strength in ovariectomized rats enhancing bone turnover

To clarify the effects of the dietary calcium (Ca)/phosphorus (P) ratio on bone mineralization under the condition of estrogen deficiency, Wistar strain female rats were ovariectomized (OVX) at 12 weeks old. At 16 weeks old, the rats were divided into three dietary groups fed varying levels of P containing 0.5% Ca: 0.25% P, Ca/P = 2; 0.5% P, Ca/P = 1; and 1.0% P, Ca/P = 0.5 respectively. This study indicates that the reduction of the dietary Ca/P ratio impairs trabecular bone turnover accompanying the acceleration of bone formation in OVX rats.     

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.     

外源钙、磷、氮对铝胁迫下杉木幼苗生长影响的调控研究

为缓解Al胁迫对杉木人工林更新的影响,本文采用水培模拟Al胁迫,引入Ca、P、NH₄⁺-N、NO₃^--N营养调控因子,探讨Al胁迫对杉木幼苗根茎生长的影响.结果表明,增加Ca或P浓度,能促进根、茎的正常生长发育,根系的形态特征明显变化,降低组织内MDA含量和POD活性.增加NH₄⁺-N浓度只能促进茎的生长,对根系发育影响不明显.增加NO₃^--N浓度对根茎生长均无明显的规律性影响.增加NH₄⁺-N和NO₃^--N浓度,能抑制MDA含量增加,并在一定范围内降低POD活性,但效果不及Ca或P明显.经回归方程拟合,得出本试验条件下营养因子有效缓解Al胁迫的阈值是:Ca/Al≥2.8,P/Al≥4.4,NH₄⁺-N/Al≥4.5(摩尔比).     

Electron-microscopic and microprobe analyses on the pigmented and unpigmented enamel of Sorex (Insectivora)

Sorex belongs to the Insectivora and has a pigmented tooth enamel due to iron. The pigmented enamel (PE) has a mean Ca/P weight ratio, analyzed by quantitative electronprobe X-ray microanalysis, of about 1.9 (mean molar Ca/P ratio 1.46), and the unpigmented enamel (UE) a Ca/P weight ratio of about 2.0 (mean molar Ca/P ratio 1.59). The PE has a higher iron content (with a value of about 8%) than the UE, as shown by microanalysis of ultrathin sections. Laser microprobe mass analysis (LAMMA) has shown that the carbonate content in the UE is higher than in the PE. In the LAMMA spectrum of the negatively charged ions the carbonate lines could be compared directly with those of negatively charged iron ions. The pigmentation is associated with a low Ca/P ratio but may transfer mechanical strength and acid resistance strength to the PE.     

Electron-microscopic and microprobe analyses on the pigmented and unpigmented enamel of Sorex (Insectivora)

Summary Sorex belongs to the Insectivora and has a pigmented tooth enamel due to iron. The pigmented enamel (PE) has a mean Ca/P weight ratio, analyzed by quantitative electronprobe X-ray microanalysis, of about 1.9 (mean molar Ca/P ratio 1.46), and the unpigmented enamel (UE) a Ca/P weight ratio of about 2.0 (mean molar Ca/P ratio 1.59). The PE has a higher iron content (with a value of about 8%) than the UE, as shown by microanalysis of ultrathin sections. Laser microprobe mass analysis (LAMMA) has shown that the carbonate content in the UE is higher than in the PE. In the LAMMA spectrum of the negatively charged ions the carbonate lines could be compared directly with those of negatively charged iron ions. The pigmentation is associated with a low Ca/P ratio but may transfer mechanical strength and acid resistance strength to the PE.     

锐齿栎林个体光合器官生长与营养季节动态

锐齿栎林单叶面积和干重的季节生长呈不同的S型曲线,叶面积叶干重比的季节变化呈不完全S型.叶从萌动到落叶持续约160d,展叶第1周,叶重量绝对增长快于叶面积的增加,之后相反.叶季节变化表现为叶面积增长迅速且持续时间较短,叶重量增加相对缓慢且持续时间较长.刚展叶时N、P、K含量很高,展叶期明显下降,落叶前最低,Ca含量季节变化则相反;Mg含量展叶期较高,之后逐渐下降且趋于稳定.叶N、P、K、Mg间呈显著的正相关,前者与Ca间呈显著的负相关.叶在生长期内具有较高的N/P、N/K,且其季节变化比单个元素含量更稳定;展叶初期K/Ca很高,之后变化逐渐稳定;叶K/Mg的季节变化趋于降低.展叶第1周叶N、P、K和Mg积累量迅速增加,继而缓慢增加,第45～50天达峰值,之后逐渐降低;Ca积累随叶龄的增加一直处于上升的趋势.叶内N、P、K、Mg和Ca积累量与叶的生长发育期有密切的关系.     

Phosphorus requirements and optimum calcium/phosphorus ratio in the diet of mrigal Cirrhinus mrigala (Ham.) fingerlings

An experiment was conducted to investigate phosphorus requirements and the optimal calcium/phosphorus (Ca/P) ratio on growth and carcass tissue composition of mrigal Cirrhinus mrigala (c. 6 g). Five purified diets were formulated to contain Ca/P ratios of 1 : 0 (0.35 : 0), 1 : 1 (0.35 : 0.35), 1 : 2 (0.31 : 0.63), 1 : 3 (0.24 : 0.71), and 1 : 4 (0.19 : 0.75), respectively. Growth performance and feed conversion ratio of mrigal responded significantly (P < 0.01) to the Ca =0.19 : P = 0.75 diet. Carcass protein, lipid, and P percentage also increased significantly with the higher P level. Based on this study, it may be concluded under the given conditions that the optimum Ca : P ratio in mrigal feed is 0.19 : 0.75.     

Decreases of calcium and phosphorus in monkey cardiac walls with development and aging

To elucidate compositional changes of the cardiac walls with development and aging, the authors investigated changes of elements in the atrial and ventricular walls of monkeys. The left and right atrial walls, left and right ventricular walls, and interatrial and interventricular septa were resected from the subjects. The subjects consisted of 17 rhesus and 13 Japanese monkeys, ranging in age from 10 d to 33 yr. The element content of the cardiac walls was analyzed by inductively coupled plasma-atomic emission spectrometry. The Ca and P contents decreased in all of the left and right atrial and ventricular walls, interatrial septa, and interventricular septa with development, whereas the S and Mg contents decreased in the left and right ventricular walls with development. Regarding the relationships among elements, significant direct correlations were found among Ca, P, Mg, and Zn in all of the left and right atrial walls, left and right ventricular walls, and interatrial and interventricular septa, with some exceptions. As Ca decresed in the cardic walls, P, Mg, and Zn decreased simultaneously in the cardiac walls. The mass ratio of Ca/P decreased gradually with Ca decrease in both the atrial and ventricular walls, but it was not constant.     

Daughter dearest: Sex‐biased calcium in mother's milk among rhesus macaques

Mother's milk provides building blocks necessary for infant development and growth postnatally. Minerals in milk are particularly important for infant skeletal development and may reflect maternal characteristics that are associated with the capacity to synthesize milk and sex‐specific developmental priorities of the infant. Using a large sample of mother–infant dyads assigned to the outdoor breeding colony at the California National Primate Research Center (N=104), we investigated the relationship of milk calcium (Ca) and phosphorus (P) concentrations and the ratio of Ca/P to maternal and infant characteristics and to other milk variables. Ca and P are largely associated with casein micelles, and as expected, both Ca and P were positively correlated with protein concentrations in milk. Neither Ca nor P concentrations were associated with maternal parity. Mothers rearing daughters tended to produce higher mean Ca concentration in milk, and consequently a higher Ca/P ratio, than did mothers rearing sons, even though protein concentration was not elevated. These results suggest that the Ca/P ratio in rhesus milk may have been under separate selective pressure from protein content to facilitate the accelerated rate of skeletal calcification that has been observed in female Macaca mulatta infants. Am J Phys Anthropol 151:144–150, 2013. © 2013 Wiley Periodicals, Inc.     

Estimation of calcium requirements for optimal productive and reproductive performance,eggshell and tibial quality in egg-type duck breeders

Optimizing the dietary calcium (Ca) level is essential to maximize the eggshell quality, egg production and bone formation in poultry. This study aimed to establish the Ca requirements of egg-type duck breeders from 23 to 57 weeks of age on egg production, eggshell, incubation, tibial, plasma and ovary-related indices, as well as the expression of matrix protein-related genes. Totally, 450 Longyan duck breeders aged 21 weeks of age were allotted randomly into five treatments, each with six replicates of 15 individually caged birds. The data collection started from 23 weeks of age and continued over the following 35 weeks. The five groups corresponded to five dietary treatments containing either 2.8%, 3.2%, 3.6%, 4.0% or 4.4% Ca. The tested dietary Ca levels increased (linear, P <0.01) egg production and egg mass, and linearly improved (P <0.01) the feed conversion ratio (FCR). Increasing the dietary Ca levels from 2.8% to 4.4% increased (P <0.01) the eggshell thickness and eggshell content. The tested Ca levels showed a quadratic effect on eggshell thickness and ovarian weight (P <0.01); the highest values were obtained with the Ca levels 4.0% and 3.6%, respectively. Dietary Ca levels affected the small yellow follicles (SYF) number and SYF weight/ovarian weight, and the linear response (P <0.01) was significant vis-à-vis SYF number. In addition, dietary Ca levels increased (P <0.05) the tibial dry weight, breaking strength, mineral density and ash content. Plasma and tibial phosphorus concentration exhibited a quadratic (P <0.01) response to dietary Ca levels. Plasma calcitonin concentration linearly (P <0.01) increased as dietary Ca levels increased. The relative expression of carbonic anhydrase 2 in the uterus rose (P <0.01) with the increment of dietary Ca levels, and the highest value was obtained with 3.2% Ca. In conclusion, Longyan duck breeders fed a diet with 4.0% Ca had superior eggshell and tibial quality, while those fed a diet with 3.6% Ca had the heaviest ovarian weights. The regression model indicated that the dietary Ca levels 3.86%, 3.48% and 4.00% are optimal levels to obtain maximum eggshell thickness, ovarian weight and tibial mineral density, respectively.     

南京栖霞山地区树木元素富集的初步研究

 本文用树木元素富集系数(T／S)来研究南京栖霞山铅锌多金属矿区树木—土壤系统中元素的富集特性。结果表明,树木对土壤中K、P二个元素的吸收基本与树种和开矿活动关系不大。黑松对Cr、Al,马尾松对Mn、Pb、Co、Ni、枫杨对P,刺槐对Mg、Na,Ti,栎对Zn、Ca、K、Fe、Sr、Ba、V,槐树对Cu均有最大的富集系数。黑松树龄对Co、K、Zn含量和Ca的富集系数有一定的影响。另外,Co—Ni、Sr—Ba的T／S曲线分别呈正相关,表现出这两组元素各自的地球化学共轭性。     

Age-related changes in strontium to calcium ratios in rat tissues

The Sr/Ca ratios in plasma, urine, bone, and soft tissues for various ages after weaning in male and female rats were determined to examine the effects of aging on the discrimination between strontium (Sr) and calcium (Ca) under physiological conditions. Age-related changes in the Sr/Ca ratios were similar in all tissues; the Sr/Ca ratios decreased rapidly until about 25-wk-old and then slowly, from that period on, reaching much lower values than in the diet. When the logarithm of the Sr/Ca ratio in each tissue was plotted against the logarithm of age, a linear relationship was observed with statistically significant (p less than 0.05) regression lines. The higher levels of Sr/Ca ratios in all tissues of the younger rats could be explained by the high efficiency of Sr absorption by the small intestine early in life. Parameters for the equations between age and Sr/Ca ratio differed with tissues, suggesting the existence of specific discrimination mechanisms in each tissue.     

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.     

Effect of dietary calcium and phosphorus restriction on calcium and phosphorus balance in young and old rats

Previous studies have shown that the serum levels of the primary regulators of calcium (Ca) and phosphorus (P) metabolism, 1,25-dihydroxyvitamin D and parathyroid hormone, may change with age. Therefore, the effect of age on the ability of the rat to maintain a positive Ca and P balance was determined. Young (1.5 months) and old (18 months) rats were divided into three groups and fed either a low-Ca, high-P diet; a high-Ca, low-P diet; or a high-Ca, high-P diet. After 14 days, the young rats were in positive Ca and P balance regardless of diet. The old rats on the low-Ca, high-P diet were in negative Ca balance and positive P balance. The old rats on the other diets were in positive Ca and P balance. The negative Ca balance of the old rats was due to decreased intestinal absorption of Ca. Intestinal absorption was assessed by determining the percentage of dietary Ca absorbed in vivo and by measuring the active transport of Ca using the everted gut sac in vitro. Intestinal P absorption showed little change with age, except for a decrease in old rats on the high-Ca, low-P diet. Renal adaptation to dietary Ca and P restriction was similar in both young and old animals. Plasma Ca levels were unchanged with age, but plasma P levels decreased with age regardless of diet. These changes in Ca balance with age may reflect the reported decrease in serum 1,25-dihydroxyvitamin D₃ levels and the slight increase in PTH levels with age. The inability of old rats to maintain a positive Ca balance in the face of Ca deprivation is consistent with a general characteristic of the aging process—the decreased ability of an organism to adapt to changes in the external environment.     

Gender Difference in Accumulation of Calcium and Phosphorus in the Left Coronary Arteries of Thais

To examine whether there were gender differences in compositional changes of the coronary artery with aging, the authors investigated the gender difference in age-related changes of elements in the left coronary arteries of Thais by direct chemical analysis. After ordinary dissections by students at Chiang Mai University were finished, the left coronary arteries were resected from Thai subjects. The Thai subjects consisted of 69 men and 34 women. The ages of the male subjects ranged from 25 to 87?years (average age?=?62.6?±?11.4?years) and of the female subjects from 24 to 86?years (average age?=?59.4?±?14.6?years). After incinerating the arteries with nitric acid and perchloric acid, the element content was determined by inductively coupled plasma-atomic emission spectrometry. The Ca and P contents tended to increase in the left coronary arteries of men with age, but the increases were not statistically significant. In the left coronary arteries of women, the Ca and P contents increased significantly and progressively with aging. In addition, the Na content increased significantly in the left coronary arteries of both men and women with aging. The differences in the average contents of Ca and P by age group were observed between the left coronary arteries of men and women. With Student's t test, significant gender differences in the average contents of Ca and P were found in both the 40s and the 70s. The Ca and P contents of the left coronary arteries in the 40s were significantly higher in men than in women. In contrast, the Ca and P contents in the 70s were significantly higher in women than in men. These results indicated that the accumulation of Ca and P in the left coronary arteries of Thais occurred at least 10?years earlier in men than in women, but a higher accumulation of Ca and P in old age occurred in the left coronary arteries of women compared with those of men. The present study revealed that there were significant gender differences in the left coronary arteries with regard to the accumulation of Ca and P with aging. It is reasonable to presume that taking clinical findings into consideration, the gender differences in the left coronary arteries may result from hormonal and/or genetic factors rather than lifestyle factors.