Bone Zinc Research Articles

Chemical Composition and Elements Concentration of Fillet, Spine and Bones of Common Carp (Cyprinus carpio) in Relation to Nutrient Requirements for Minerals.

The aim of the study was to compare the content of major components, selected elements and heavy metals in the fillet, spine and bones of a carp (Cyprinus carpio). Moreover, the extent to which a prepared portion of carp tissue (100 g of fillet and 10 g of carp spine or bones) met the requirements for analyzed elements in adults (women and men) and children was calculated. The proximate composition (total protein, total lipid, ash, moisture) and mineral content of the fish samples were determined. The nutrient composition presented fluctuations among the different tissues. Moisture was the main constituent in the fillet and in the spine with 77.8% and 56.0%, respectively, whereas in bones, the main ingredient was ash (36.2%). All carp tissues were good sources of protein, with 16.5%, 21.0% and 17.0% in spine, bones and fillet, respectively. The most abundant main elements were the potassium in the fillet (4005 mg kg-1) and calcium in the bones (116,463 mg kg-1). The most abundant trace elements were iron in fillet and zinc in bones and spine. Carp meat can be considered a safe foodstuff in terms of concentrations of Hg, Pb and Cd, as the levels of these contaminants were less than FAO and European Commission maximum guidelines.

Key Trace Elements Zinc and Magnesium Levels Decline After Fracture in a Rat Model

Category: Basic Sciences/Biologics; Basic Sciences/Biologics Introduction/Purpose: Zinc and magnesium are crucial for bone health, and their deficiencies can lead to impaired bone metabolism and repair. Although enhancing their bioavailability has been linked to better fracture healing, their levels during healing have not been studied. We hypothesized that zinc and magnesium levels transiently decrease at the fracture site compared to intact bone. This study is the first to explore temporal trace element levels during the initial stages of fracture healing. The findings will reveal when each element changes its concentration at the fracture site, which is associated with specific functions necessary for appropriate healing. Understanding the connection between trace element concentration and repair processes could lead to more effective treatment or supplementation during fracture healing. Methods: Following induction of a femur fracture in male BB Wistar rats, injured and intact contralateral femurs were harvested at 1- (n=3), 3- (n=4), and 7-days (n=3) after fracture. Fracture segments 10mm in length were resected 5mm from the center of the callus in either direction. Contralateral non-fractured femur segments were resected from the same region within the femoral diaphysis. Samples were analyzed via inductively coupled mass spectrometry using an Agilent ICP-MS 7900 (Agilent Technologies, Santa Clara, CA). Data was converted from ppb to percent weight zinc and magnesium per weight of bone (w/w%). The difference between zinc and magnesium in contralateral intact bone vs. fractured bone was calculated and averaged (∆) for each group. The average % change were also determined. An independent sample two-tailed t-test was performed comparing average w/w% of zinc and magnesium between fracture and contralateral samples. A p-value of < 0.05 was considered significant. Results: After 1-day post-fracture, there was a -29.09 average % change in zinc levels (∆ 6.90x10^-03 ± 5.05x10^-03) (p = 0.033) and a -25.76 average % change in magnesium levels (∆ 1.21x10^-01 ± 7.36x10^-02 w/w%) (p = 0.241) between fractured and non- fractured femurs. After 3-days post-fracture, there was a -22.51 average % change in zinc levels (∆ 5.45x10^-03 ± 3.95x10^-03 w/w%) (p = 0.022) and a -33.07 average % change in magnesium levels (∆ 1.84x10^-01 ± 1.05x10^-01 w/w%) (p = 0.025). After 7- days post-fracture, there was a -9.40 average % change in zinc levels (∆ 1.90x10^-03 ± 3.98x10^-03) (p = 0.377) and a -17.88 average % change in magnesium levels (∆ 9.04x10^-02 ± 1.24x10^-01 w/w%) (p = 0.159) between fractured and non-fractured femurs. Conclusion: Previous research has established the significance of trace elements, namely zinc and magnesium, in the process of fracture healing. Zinc has been shown to improve fracture healing, while magnesium has been found to play a role regulating inflammation during early fracture healing. The findings of this study corroborate our hypothesis that levels of these elements transiently decline following fracture. By evaluating these changes in trace element levels, we can gain a better understanding of their function in the fracture healing process. These observations may offer insight into potential therapeutic approaches utilizing zinc and magnesium for fracture healing in the future.

Effects of Various Copper Sources and Concentrations on Performance, Skeletal Growth, and Mineral Content of Excreta in Broiler Chickens.

The experiment was designed to study the effect of supplemental sources and concentrations of copper on the performance and development and mineralization of tibia bones in broiler chickens. A 42-day feeding experiment was conducted utilising three copper sources, including copper sulphate (CuS), copper chloride (CuCl), and copper propionate (CuP), each with four different concentrations, i.e. 8, 100, 150, and 200mg/kg. The body weight gain with 200mg Cu/kg food was noticeably higher during the first 4-6weeks of age. Due to the interaction between Cu sources and levels, there was no significant change in the body weight gained. The feed intake during various growing phases did differ significantly neither the main effect nor the interaction between different copper sources and levels. A CuP-supplemented diet (200mg/kg food) considerably (P ≤ 0.05) improved the feed conversion ratio between 4-6 and 0-6weeks. At the end of the experiment, a total of 72 tibia bones, i.e. six for each treatment were collected. A metabolic trial was conducted to look into mineral retention in broiler chickens on the final 3days of the trial (40-42days). Increased tibia bone zinc (Zn) levels were seen with the addition of 8mg Cu/kg of Cu chloride, 100mg Cu/kg of Cu propionate, 8mg Cu/kg of Cu sulphate, and 8mg/kg of Cu propionate to the diet. At higher levels of Cu (150 and 200mg/kg diet), there was a significantly (P ≤ 0.01) reduced tibia Zn content. Cu sulphate treatment group had higher (P ≤ 0.01) tibia Cu content (8mg Cu/kg diet). Cu sulphate supplemented diet had a greater excreta Zn content (P ≤ 0.01) than Cu chloride supplemented diet, and Cu propionate supplemented diet had the lowest excreta Zn content. Excreta with a higher Fe concentration were found in diets supplemented with copper sulphate and copper chloride (P ≤ 0.05) than in diets supplied with copper propionate. Thus, it may be concluded that feeding dietary Cu concentrations up to 200mg Cu/kg diet, regardless of the different sources, had no negative effects on bone morphometry and mineralization parameters with the exception of a decrease in the tibia's zinc content.

Bone Zinc Is Poorly Released in Young, Growing Rats Fed Marginally Zinc-Restricted Diet

The effect of marginal zinc restriction on bone zinc release was studied. Male weanling rats were fed zinc-adequate diet (12 mg zinc/kg diet) for 1 wk, intubated with 65Zn, refed the zinc-adequate diet for an additional week, and divided into one baseline group and five marginally zinc-restricted groups (6 mg/kg) and five corresponding zinc-adequate pair-fed groups. Significantly lower (P < 0.05) 65Zn radioactivity (10-20%) in the first week was observed in femurs of rats fed the marginally zinc-restricted diet without further change in the following weeks. Pair-fed rats showed higher 65Zn radioactivity in femurs in the second week, and the level was maintained. Similar results were found in tibia 65Zn radioactivity. Muscle zinc concentration was higher in the first week (P < 0.05) but subsequently returned to baseline levels in the second week through the fifth week. The results support the existence of two zinc pools in the skeleton, one a small, rapidly turning-over pool (10-20% in size), and the other a slowly turning-over pool. When rats suffer marginal zinc restriction, zinc from the readily turning-over bone pool is utilized for soft tissue needs, followed by decreased growth rate to maintain zinc homeostasis.

Growth, nutrient retention, wastes output and nonspecific immunity of juvenile snakehead Channa argus in response to dietary zinc levels

An 8-week feeding trial was conducted to investigate the effects of dietary zinc levels on growth, nutrient retention, waste output and nonspecific immunity of juvenile snakehead Channa argus. Six isonitrogenous (485 g/kg crude protein) and isolipidic (106 g/kg crude lipid) diets were formulated, with supplementation of graded levels of hydrated zinc sulphate at 0 (diet Zn0), 0.2 (diet Zn0.2), 0.4 (diet Zn0.4), 0.7 (diet Zn0.7), 1.0 (diet Zn1.0) and 1.3 g/kg (diet Zn1.3), which provided the actual dietary zinc concentration of 56, 99, 140, 235, 301 and 375 mg/kg respectively. The highest weight gain rate was found in fish fed diet Zn0.7. Lower feed intake and feed conversion ratio, while higher retention efficiencies of nitrogen and phosphorus, were found in fish fed diets Zn0.2, Zn0.4 and Zn0.7 than in fish fed diets Zn0 and Zn1.3. Zinc retention efficiency decreased with the increase IN dietary zinc levels. Contents of zinc in whole body and spinal bone increased with dietary hydrated zinc sulphate increased from 0 to 0.7 g/kg. Higher nitrogen and phosphorous waste were found in fish fed diets Zn0, Zn1.0 and Zn1.3 than in fish fed diets Zn0.2, Zn0.4 and Zn0.7, and lower zinc waste was found in fish fed diets Zn0, Zn0.2, Zn0.4 and Zn0.7 than in fish fed diets Zn1.0 and Zn1.3. Higher serum C4 and IgM were found in fish fed diets Zn0.7, Zn1.0 and Zn1.3 than in fish fed diet Zn0, Zn0.2 and Zn0.4. Our results showed that dietary supplementation of hydrated zinc sulphate needed to promote fast growth, keep good nutrient retention and immunological capacity, and reduce waste discharge in juvenile snakehead should be 0.7 g/kg (235 mg/kg zinc concentration).

Correction: Quantification of local zinc and tungsten deposits in bone with LA-ICP-MS using novel hydroxyapatite–collagen calibration standards

Correction for ‘Quantification of local zinc and tungsten deposits in bone with LA-ICP-MS using novel hydroxyapatite–collagen calibration standards’ by Cassidy R. VanderSchee et al., J. Anal. At. Spectrom., 2021, 36, 2431–2438, DOI: 10.1039/D1JA00211B.

Association between bone trace elements and osteoporosis in older adults: a cross-sectional study.

Objectives:Metal micronutrients deficiency may be one of the risk factors for the development of osteoporosis. This study aimed to measure the trace element contents in human bone tissue to analyze the relationship between micronutrients and osteoporosis.Design:A cross-sectional survey was performed on data from 51 elderly patients with proximal femoral fracture.Methods:The concentrations of calcium, phosphorus, manganese, iron, copper, and zinc in bone tissue samples from 51 elderly patients with proximal femoral fracture were determined by energy-dispersive X-ray fluorescence (EDX). Subjects were divided into osteoporosis and non-osteoporosis groups according to their bone mineral density (BMD) T-score values. The difference in metal elements concentrations in bone tissue between the two groups was compared, and the role of metal elements in osteoporosis was discussed.Results:There was no statistical difference in age, sex, body mass index (BMI), serum albumin, biochemical blood indices, and bone turnover markers between the two groups. The Mann–Whitney U test was used to compare the difference in metal elements concentrations in bone tissue samples between the two groups. The results showed that manganese, copper, and zinc concentrations in the cancellous bone were significantly higher in the non-osteoporosis group than in the osteoporosis group. Multivariate logistic regression analysis indicated that high bone zinc concentration [odds ratio = 0.26, 95% confidence interval (CI) = 0.075–0.928, p = 0.038] was negatively correlated with osteoporosis.Conclusion:Manganese, copper, and zinc play an essential role in bone mineralization and metabolism. Among them, zinc may be most closely related to osteoporosis and play a key role in bone development and maintenance of bone mass. Therefore, we believe that the design of zinc-rich compounds or nutrients as a new complementary factor to increase the intake of zinc for the elderly could be able to prevent and intervene in the occurrence of osteoporosis in the early stage.

Zinc isotopes from archaeological bones provide reliable trophic level information for marine mammals

In marine ecology, dietary interpretations of faunal assemblages often rely on nitrogen isotopes as the main or only applicable trophic level tracer. We investigate the geographic variability and trophic level isotopic discrimination factors of bone zinc 66Zn/64Zn ratios (δ66Zn value) and compared it to collagen nitrogen and carbon stable isotope (δ15N and δ13C) values. Focusing on ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from multiple Arctic archaeological sites, we investigate trophic interactions between predator and prey over a broad geographic area. All proxies show variability among sites, influenced by the regional food web baselines. However, δ66Zn shows a significantly higher homogeneity among different sites. We observe a clear trophic spacing for δ15N and δ66Zn values in all locations, yet δ66Zn analysis allows a more direct dietary comparability between spatially and temporally distinct locations than what is possible by δ15N and δ13C analysis alone. When combining all three proxies, a more detailed and refined dietary analysis is possible.

Bone Health in Aging Men: Does Zinc and Cuprum Level Matter?

The aim of this study was to assess the associations of serum and bone zinc (Zn) and cuprum (Cu) with bone mineral density (BMD) and content (BMC), markers of bone turnover, and sex hormones. The study group comprised 144 men treated with total hip replacement due to hip osteoarthritis. We measured total, free, and bioavailable testosterone, estradiol, and sex-hormone-binding globulin (sex hormones), as well as parathyroid hormone, osteocalcin, carboxy terminal collagen crosslinks, and N-terminal propeptide of type I procollagen (markers of bone turnover). Total body BMD, BMC, total and visceral fat, and appendicular skeletal mass (ASM) were measured using dual-energy X-ray absorptiometry. ASM index, and total and visceral fat were positively correlated with BMD. Bone Zn correlated neither with sex hormones nor with bone turnover markers; however, it was positively associated both with BMD and with BMC, while bone Cu (as opposed to serum Cu) was not. In multiple regression, the ASM index, Zn/Cu ratio (in both the serum and the bone), and serum Cu concentration were significantly associated with BMD and BMC after adjustment for age and body mass index (BMI). Our results suggest that the Zn/Cu ratio in both the serum and the bone may exert a significant positive effect on total BMD and BMC.

Quantification of local zinc and tungsten deposits in bone with LA-ICP-MS using novel hydroxyapatite-collagen calibration standards.

Tungsten has recently emerged as a potential toxicant and is known to heterogeneously deposit in bone as reactive polytungstates. Zinc, which accumulates in regions of bone remodeling, also has a heterogenous distribution in bone. Determining the local concentrations of these metals will provide valuable information about their mechanisms of uptake and action. A series of bone (BN), 7:3 hydroxyapatite:collagen (HC), and hydroxyapatite (HA) standards were spiked with tungsten and zinc and used as calibration standards for laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis of bone tissue. The analytical performance of these standards was studied and validated at different step sizes using NIST SRM 1486 Bone Meal. The effect of matrix-matched calibration was assessed by comparing the calibration with BN and HC standards, which incorporate both inorganic and organic components of bone, to that of HA standards. HC standards were found to be more homogenous (RSD < 10%) and provide a linear calibration with better accuracy (R2 > 0.994) compared to other standards. The limits of detection for HC at a 15 μm step size were determined to be 0.24 and 0.012 μg g-1 for zinc and tungsten, respectively. Using this approach, we quantitatively measured zinc and tungsten deposits in the femoral bone of a mouse exposed to 15 μg mL-1 tungsten for four weeks. Localized concentrations of zinc (942 μg g-1) and tungsten (15.7 μg g-1) at selected regions of enrichment were substantially higher than indicated by bulk measurements of these metals.

Microflower like Zinc Oxide/Cerium, Lanthanum Substituted Hydroxyapatite Bilayer Coating on Surgical Grade Stainless Steel for Corrosion Resistance, Antibacterial and Bioactive Properties

The growing evidence of beneficial role of zinc in bone has increased the interest of developing zinc-containing biomaterials for medical applications and specifically biocompatible coatings that can be deposited on metallic implants to benefit from their load-bearing capabilities. In present work, zinc oxide/cerium, lanthanum substituted (ZnO/Ce,La-HAP) hydroxyapatite bilayer coatings have been fabricated by electrodeposition technique. As developed, ZnO/Ce,La-HAP bilayer coatings were then structurally, morphologically and chemically characterized using Fourier-transform infrared spectroscopy(FT-IR), X-ray diffraction (XRD), higher resolution scanning electron microscopy (HRSEM) and energy dispersive X-ray spectroscopy (EDAX). The properties of corrosion performance of 316L SS were explored in Ringers solution using electrochemical analysis. The potentiodynamic polarization and impedance analysis demonstrated that the anticorrosion behavior of 316L SS was significantly increased by the bilayer coating. Cell viability in vitro, antibacterial activity and live/dead assay of ZnO/Ce,La-HAP bilayer coating were investigated. Hence, development of ZnO/Ce,La-HAP bilayer coating on 316L SS to make it suitable for biomedical applications.

Disruption of Bone Zinc Metabolism during Postnatal Development of Rats after Early Life Exposure to Cadmium.

This current study was conducted to investigate whether bone tissue impairment induced by early life exposure to cadmium (Cd) during postnatal development could result from disruption to zinc (Zn) metabolism. For this reason, the offspring from mothers receiving either tap water, Cd, Zn or Cd + Zn during gestation and lactation periods were euthanized at PND21 and PND70. At the end of the lactation period (PND21), our results showed that exposure to Cd increased Cd accumulation and Zn depletion in the femur. Furthermore, calcium (Ca) level was reduced. At the molecular level, Cd induced an increase of MT-1 expression and caused an upregulation of ZIP2 accompanied with a down-regulation of ZnT5. Runx2, ALP, colα-1 and Oc mRNA levels were also decreased. In plasma, IGF-1 and osteocalcin concentrations were decreased. Further, Cd altered femoral growth by generating changes in the growth plate. Consequently, the toxic effect of Cd persisted at adult age (PND70) by decreasing bone volume (%BV/TV), bone mineral density (BMD) and Ca content and by increasing trabecular separation (Tb.Sp) in the distal femur. Interestingly, Zn supply provided total or partial corrections of several toxic effects of Cd. These data suggest that the increases of Zn bioavailability as well as the reduction of Cd accumulation in the femur following the changes in ZIP2 and ZnT5 expression are part of the mechanism involved in Zn protection against Cd toxicity on bone tissue.

Dietary Calcium to Digestible Phosphorus Ratio for Optimal Growth Performance and Bone Mineralization in Growing and Finishing Pigs.

Simple SummaryMinimizing the use of dietary non-renewable mineral phosphates improves the sustainability of phosphorus use in growing-finishing pigs. As the phosphorus metabolism is closely linked to calcium, this experiment compared three dietary calcium to digestible phosphorus ratios within two phosphorus levels to determine the optimum levels for growth performance and bone mineralization. The lowest calcium level was insufficient for an efficient metabolic use of P, the medium level was sufficient to maximize growth performance and highest level further improved bone mineralization. The low digestible phosphorus level enabled a complete removal of supplemented mineral phosphates in the finisher period, which resulted, per pig, in a decrease of its use by 65% and a decrease of the calculated P excretion by 41%, without impaired growth performance. However, a reduced bone mineralization was observed. This study shows that there is potential to reduce the digestible phosphorus compared to practiced levels in grower–finisher pigs and shows that the optimal calcium to digestible phosphorus ratio needs to be maintained at the upper range of the actually available recommendations.Within the context of maximizing the use of dietary phosphorus, a growing-finishing pig study was conducted to determine the optimal total dietary calcium (Ca) to digestible phosphorus (dP) ratio and to verify the possibility of mineral phosphate removal during the finishing period on growth performance and mineral status. The potential for replacing chemical and mechanical bone properties by dual energy X-ray absorptiometry (DXA) measures on non-dissected feet was also verified. Three Ca to dP ratios (2.2:1, 2.5:1 and 2.8:1) within two dP levels (P+, P–) were fed during 91 days to 84 pigs. The grower and finisher P+ diets contained 3.0 and 2.4 and P– diets contained 2.5 and 1.7 g dP/kg, respectively. Growth performance and blood serum mineral content were independent of treatments, except that 2.2:1 impaired finisher feed conversion ratio compared to 2.5:1 and 2.8:1. Urinary P concentration increased by 37% in 2.2:1 compared to 2.5:1 and 2.8:1. Maximal load on bone and DXA mineral density were reduced in 2.2:1 compared to 2.8:1. Bone ash and volumetric density were reduced in 2.2:1 and 2.5:1 compared to 2.8:1. Diet P– reduced bone ash, maximal load, volumetric density and DXA bone mineral content and density. No interaction was observed between Ca and dP level. Therefore, 2.2:1 was insufficient for an efficient metabolic use of P, 2.5:1 was sufficient to maximize growth performance and 2.8:1 further improved bone mineralization. Increasing dietary Ca did not impair bone zinc content. Diets P– without supplemented mineral phosphates during the finisher period resulted, per pig, in a decrease of its use by 65% and of the calculated P excretion by 41%, without impaired growth performance. Finally, DXA data responded to dietary treatments as did labor intensive chemical and mechanical bone properties.

Therapeutic role of bone marrow-derived stem cells and zinc sulfate for reduction of liver fibrosis

Introduction: Hepatic fibrosis is considered as the initial state of any chronic hepatic disease; progression causes accumulation of extracellular matrix (ECM) and develops into cirrhosis. In case of liver failure, transplantation was considered as the only suitable therapy but due to the hurdles in transplantation, therapy using stem cells was promoted. Mesenchymal stem cells (MSCs) are widely used for the treatment of a variety of diseases. Oxidative stress at the damage site causes poor MSC proliferation and engraftment. Thus, it is necessary to induce antioxidants with MSCs to enhance potency.&#x0D; Methods: To explore the therapeutic potential of zinc sulfate (ZnSO4) and MSCs on carbon tetra chloride (CCl4)-induced hepatic toxicity, 6-8 week-old female albino mice (BALB/c) were used. Initially, mice were infected with CCl4 and then intra-peritoneally injected with MSCs only, ZnSO4 only, or a combination of MSCs and ZnSO4. MSCs were isolated from femur and tibia of mice, and were cultured under control conditions.&#x0D; Results: The morphological results revealed that in contrast to MSC-only therapy, ZnSO4 enhanced the therapeutic potential of MSCs when administered to CCl4-injured mice. Biochemically, level of serum Alanine Transaminase (ALT) and total bilirubin was found to be significantly decreased in ZnSO4 + MSC transplanted mice. Histopathological examination also revealed that ZnSO4 + MSC transplantation induced a strong anti-apoptotic effect on CCl4-injured liver. Reverse transcription polymerase chain reaction (RT-PCR) detected a noteworthy anti-fibrotic effect of MSCs in the presence of ZnSO4, down-regulation of apoptotic marker (Bax), and up-regulation of anti-apoptotic (Bcl-xl) and hepatic (Albumin) markers.&#x0D; Conclusion: Thus, it was concluded that the presence of ZnSO4 reduced oxidative stress, enhanced the proliferation rate of MSCs, and significantly attenuated hepatic fibrosis.&#x0D;

Addressing K/L-edge overlap in elemental analysis from micro-X-ray fluorescence: bioimaging of tungsten and zinc in bone tissue using synchrotron radiation and laser ablation inductively coupled plasma mass spectrometry.

Synchrotron radiation micro-X-ray fluorescence (SR-μXRF) is a powerful elemental mapping technique that has been used to map tungsten and zinc distribution in bone tissue. However, the heterogeneity of the bone samples along with overlap of the tungsten L-edge with the zinc K-edge signals complicates SR-μXRF data analysis, introduces minor artefacts into the resulting element maps, and decreases image sensitivity and resolution. To confirm and more carefully delineate these SR-μXRF results, we have employed laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to untangle the problem created by the K/L-edge overlap of the tungsten/zinc pair. While the overall elemental distribution results are consistent between the two techniques, LA-ICP-MS provides significantly higher sensitivity and image resolution compared with SR-μXRF measurements in bone. These improvements reveal tissue-specific distribution patterns of tungsten and zinc in bone, not observed using SR-μXRF. We conclude that probing elemental distribution in bone is best achieved using LA-ICP-MS, though SR-μXRF retains the advantage of being a non-destructive method with the capability of being paired with X-ray techniques, which determine speciation in situ. Since tungsten is an emerging contaminant recently found to accumulate in bone, accurately determining its distribution and speciation in situ is essential for directing toxicological studies and informing treatment regimes. Graphical abstract Tungsten and zinc localization and uptake in mouse femurs were imaged by synchrotron radiation, left, and by laser ablation ICP-MS, right. The increased resolution of the LA-ICP-MS technique resolves the problem of the overlap in tungsten's L-edge and zinc's K-edge.

Transcriptional Regulation of Zinc Transporters in Human Osteogenic Sarcoma (Saos-2) Cells to Zinc Supplementation and Zinc Depletion.

Bone is a passive storage organ for zinc, which contains about 30% of the total body zinc. However, during extreme zinc deficiency, only a small fraction of zinc is released in contrast to other tissues where zinc is released like monocytes or conserved, e.g., skeletal muscle. Zinc plays an important role in bone tissue remodeling. Zinc homeostasis is regulated by several zinc transporters (ZnTs) and importers (ZIPs), but their expression dynamics concerning zinc status of bone cells is not well understood. The study aimed to elucidate the effects of zinc supplementation and depletion on the transcript levels of various zinc transporters. Saos-2, a human osteoblastic cell line, was used as representative bone tissue. Zinc sulfate was used for simulating sufficient zinc status whereas TPEN, a zinc chelator, was used to simulate zinc-deficient state. Expression of various transcripts was measured by qRT-PCR. Subcellular localization of ZnT-1 was carried out by immunofluorescent microscopy, and Western Blotting was carried out to measure the expression of ZnT-1 at the protein level. Among the export transporters the transcript levels of MT, ZnT-1 showed higher levels in zinc sufficient and lower levels in TPEN treated cells. Expression of ZnT-4 was decreased under both the conditions. ZIP-6 and ZIP-13 were downregulated in zinc sufficiency, and ZIP-10 upregulated probably to prevent an excess zinc accumulation in bone cells. Further, ZnT-1 was found to be localized in the nuclear region of SaOS-2 cells. ZnT-1, ZnT-4, ZIP-6, ZIP-11, ZIP-10, and ZIP-13 along with MT may be responsible for maintaining bone zinc homeostasis.

Metabolic changes in the bone tissue of animals in conditions of experimental cadmium intoxication

Objective: to investigate the features of metabolic processes, bioelement composition and mineral density of the bone tissue of white rats (sexually mature males) in conditions of defeat by cadmium ions.Materials and methods. The toxicant (Сadmium chloride, CdCl2, 1,2 mg/kg) was administered to animals for 10 days, and then removed from the experiment on days 1, 14 and 28. The blood and femurs were investigated. Blood levels of calcium-phosphorus metabolism, acidi and alkaline phosphatases, magnesium, Нydroxyproline concentrations were studied by standardized methods using reagent kits, as well as the level of Рarathyroid hormone and Сalcitonin in the development of intoxication. In the ash of the femurs, the content of osteotropic bioelements and toxic cadmium was determined. The bone mineral density (BMD)was investigated using standard x-ray densitometry.Results. An increase in the concentration of total and ionized calcium on the background of increased secretion of Рarathyroid hormone and reduced Сalcitonin has been established; decreased activity of alkaline phosphatase, increased acidi phosphatase, especially on the 14-th day. In animals, an increase in the concentration of Нydroxyproline was observed in the blood (2,5–3,5 times) and a decrease in magnesium. When determining the content of osteotropic bioelements in the ash of the femoral bones of rats under conditions of CdCl2 exposure, a decrease in the content of Сalcium, Мagnesium, Сopper and Zinc in the femoral bones (by 13–45 %) against the background of a significant increase in the content of Cadmium (9,8 times) was found. Also, there is a decrease in BMD, especially low values recorded on the 14th day.Conclusions. The results of complex studies show that under conditions of introduction of CdCl2 into animals, metabolic processes in bone tissue are disturbed, dismicroelementosis develops, the mineral phase of the bone is demineralized, its collagen matrix is destroyed, and resorption dominates over osteosynthesis

An Analysis of Systematic Elemental Changes in Decomposing Bone.

The aim of this pilot study was to investigate compositional changes in bone during decomposition. Elemental concentrations of barium, calcium, iron, potassium, magnesium, zinc and phosphorus in porcine bone (as an experimental analog for human bone) were analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The samples were taken from porcine bone subjected to shallow burial and surface depositions at 28-day intervals for a period of 140 days. Results indicated that ICP-OES elemental profiling has potential to be developed as a forensic test for determining whether a bone sample originates from the early stages of soft tissue putrefaction. Significant changes in iron, sodium and potassium concentrations were found over 140 days. These elements are known to be primarily associated with proteins and/or tissue fluids within the bone. Changes in their respective concentrations may therefore be linked to dehydration over time and in turn may be indicative of time since deposition.

Dual Action of Zinc in Bone and Vascular Calcification

Osteogenic calcification is a normal physiological process in bone tissue, anywhere else like the blood vessel, it is a pathological process which is so‐called calcification paradox. The retarded skeletal growth in animals and man is the major sign of zinc inadequacy, which implies the involvement of zinc in osteogenic calcification.Our previous studies showed that inadequate zinc level in osteoblasts decreased osteogenic activities by decreasing extracellular matrix calcification, mainly through the inhibition of alkaline phosphatase (ALP) expression and activity, and by down‐regulation of osteoblast differentiation marker genes (osteopontin, osteocalcin and collagen type I), which is regulated through the reduced and delayed expression of bone‐specific transcription factor Runx2. Therefore, it seems zinc can be a stimulator in bone formation which includes osteogenic bone matrix calcification.Meanwhile, there is emerging evidence that zinc can protect against vascular damage and therefore may decrease the incidence of atherosclerotic plaque calcification. Our recent study using rat aortic smooth muscle cell line (A7r5) and rat primary vascular smooth muscle cells (pVSMC) showed that inadequate zinc level in VSMCs increased VSMC calcification and this calcification is paralleled with VSMC apoptotic pattern, rather than osteogenic calcification mode. In mice study using atherosclerotic model (ApoE null mouse), zinc deficiency promotes aorta Ca and P deposition (vascular calcification), while it decreases Ca and P contents in femur (bone calcification). The findings from our in vitro (osteoblasts and VSMCs) and in vivo (atherosclerotic ApoE null mouse) studies suggest that zinc may have a reciprocal role for calcification in bone (hard tissue) and blood vessel (soft tissue). It can be suggested that zinc may have a potential for therapeutic strategy for atherosclerosis as well as osteopoprosis, both of which involve the process of calcification.Support or Funding Information(Supported by the National Research Foundation of Korea, NRF‐2011‐0014535)

15. Comparison of the Effect of a Standard Inclusion Level of Inorganic Zinc to Organic Form at Lowered Level on Bone Development in Growing Male Ross Broiler Chickens

Abstract The purpose of this study was to compare the effect of a standard inclusion level of inorganic zinc to organic form at lowered level on the bone development in growing male Ross 308 chickens, assessed on the basis of mechanical, geometric, and histomorphometric parameters of limb bone, and bone zinc content, as well as hormones of somatotropic axis. A total of 80 one-day-old male Ross broiler chickens were randomly allocated to 2 groups of 40 chickens each. The control group was fed with a corn-soybean meal basal diet providing the recommended zinc amount (100 mg×kg-1) from zinc oxide, and the experimental group was supplemented with glycinate chelate providing 25% of the total requirement of the microelement recommended for Ross 308 broiler chicks. The mechanical and histomorphometric parameters and geometry of tibia were determined as well as the serum concentration of growth hormone, IGF-1, osteocalcin and leptin. The serum concentration of Zn, Cu, Ca, Mg, Fe, P and zinc bone content were determined. The results showed that birds fed with the diet supplemented with organic zinc in the amount of 25% of the recommended amount did not exhibit weight and general growth disorders and had an unchanged concentration of growth hormone, leptin, and IGF-1. The serum concentration of Zn, Cu, Ca, Mg, Fe, P did not differ between groups. The contents of zinc detected in bones in the controls and the group supplemented with the organic source did not differ as well. Although tibial mechanics and geometry remained unchanged, histomorphometry revealed a disproportionately large osteoporotic bone. The changes in tibial trabecular bone as a result of the diet supplemented with glycinate chelate only in 25% of the total requirement of the microelement recommended for Ross 308 broiler chicks seems to be insufficient for tibia development.