Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PHOSPHORUS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed1982

[Effect of diets low in phosphorus and high in dietary calcium on phosphatemia and phosphorus and calcium levels in rumen contents of sheep].

Four semi-purified diets with different calcium (Ca) and phosphorus (P) contents were given to adult sheep at a level of 1 kg daily plus 100 g of straw. The phosphorus was supplied as dicalcium phosphate, almost insoluble in rumen fluid. In the preliminary period, all the animals (16) were fed the test diet (NCa-NP) containing 8.4 g of Ca and 3.3. g of P. In the experimental period (table 3) two trials were carried out. In trial 1, two groups of 5 sheep each were given for 5 weeks a diet low in P (1 g/kg) and either low (2 g/kg) (diet BCa-BP) or high (10 g/kg) (diet HtCa-BP) in calcium. In trial 2, which lasted for 19 weeks, the HtCa-BP diet was compared to a high Ca (10 g/kg) normal P (3.3 g/kg) diet (diet HtCa-NP); two groups of 2 sheep each were fed both these diets every 3 hours, and one group (HtCa-BP) was fed twice daily. The concentration of ultrafilterable inorganic Ca (CaiU) in the rumen contents was related to the Ca level of the diet (tables 4, 5). However, individual variations were high and CaiU concentrations were negatively correlated to rumen pH (fig. 7). When diets adequate in P were fed, ruminal concentrations of ultrafilterable P (PiU) were rather high (400-490 mg/l), showing the importance of endogenous P supply in the rumen. With an adequate P supply, a high Ca intake had no effect on either plasma or ruminal PiU. When low P diets were fed, there was a steady decrease in plasma Pi from 6 to 3.5 mg P/100 ml and in ruminal PiU from 500 mg/l to values lower than 300 mg/l up to 5-6 experimental weeks. These decreases were greatest with high Ca intake (HtCa-BP diet) (figs. 2, 3), some animals being markedly affected (ruminal PiU values lower than 20 mg/l). However, the decreases in ruminal PiU were less pronounced with frequent feeding than with feeding twice a day. Considering all the results obtained, ruminal PiU concentrations were positively correlated with plasma Pi concentrations (r = + 0.77; n = 75) (fig. 8). Therefore, high Ca intake can enhance the response to P deficiency and reduce further plasma Pi concentrations and levels of available P in the rumen. Microbial P requirements may not be satisfied in such conditions, which would reduce ruminal microbial digestion in some animals.

Animals↗
PubMedDate not supplied

[Effect of excess phosphorus consumption on a phosphorus-calcium metabolism and bone tissue of rats under hypokinesia].

The exposure of rats fed with the diet containing Ca : P = 1 : 0.5 - 1 : 3 to hypokinesia produced hypocalcemia, osteoporosis and increased renal calcinosis. The reduced phosphorus consumption (Ca : P = 1 : 0.5 - 1 : 1) prevented these disorders in the intact animals and increased bone density in the hypokinetic rats. The excessive phosphorus consumption caused hypocalcemia, hyperphosphatemia and slight osteoporosis in both intact and hypokinetic rats, with the changes being more pronounced in those latter. It is concluded that the diet with Ca : P = = 1 : 0,5-1 : 1 is optimal for hypokinetic rats.

Alkaline Phosphatase↗
PubMedDate not supplied

Determination of total phosphorus in foods by colorimetric measurement of phosphorus as molybdenum blue after dry-ashing: NMKL interlaboratory study.

A spectrophotometric method in which the sample is dry-ashed in the presence of zinc oxide, and total phosphorus content is measured colorimetrically as molybdenum blue was evaluated by 12 participating laboratories from the Nordic countries. The study included potato flour, sausage, cold ham, infant formula powder, cheese, and skimmed milk powder. The materials were presented to the participants as 12 randomly coded samples of 2 blind duplicates of each material. The phosphorus content of the materials varied between 0.076 and 0.96 g/100 g. The relative standard deviation for repeatability of the method varied from 1.1% for 0.96 g phosphorus/100 g to 5.4% for 0.29 g phosphorus/100 g. The relative standard deviation for reproducibility varied from 3.6% for 0.96 g phosphorus/100 g to 7.7% for 0.23 g phosphorus/100 g.

Colorimetry↗
PubMed1993

Calcium and phosphorus retention in the preterm infant during total parenteral nutrition. A comparative randomised study between organic and inorganic phosphate as a source of phosphorus.

The preterm infant fed parenterally is prone to some demineralisation due in part to insufficient Calcium (Ca) and Phosphorus (P) retention. In an attempt to augment Ca and P retention, we prepared a standardised parenteral solution containing calcium gluconate and glucose-1-phosphate (Phocytan) as source of phosphorus, yielding a daily supply of 75 mg/kg Ca and 45 mg/kg P. 28 very low birthweight infants were randomly assigned to receive either this solution (high Ca P ; n = 15) or a conventional formulation containing calcium gluconate and potassium mono- and dibasic phosphate delivering 42 mg/kg Ca and 36 mg/kg P daily (low Ca P ; n = 13). In the high Ca P daily retention was respectively 80% and 99% for Ca and P whereas in the low Ca P group, retention was 70% and 82%. Serum parathormone levels were significantly lower in the high Ca P group. We conclude that parenteral nutrition with a new high Ca P supplement results in an augmented Ca and P retention in very low birthweight infants. This may help to prevent neonatal bone demineralization.

Journal Article↗
PubMed2003

Synthesis and structural studies of binuclear platinum(II) complexes with a novel phosphorus-nitrogen-phosphorus ligand.

The new pyridinediphosphinite ligand PONOP (1) was synthesized in one step from 2,6-pyridinedimethanol and diphenylchlorophosphane. Reaction of 1 with PtCl(2)(PhCN)(2) led to the neutral homobimetallic complex [Pt(2)Cl(4)(PONOP)(2)] (2), where the benzonitriles have been substituted by the phosphorus atoms of 1. The X-ray structure of 2 revealed a metallamacrocycle where the pyridines remained free. Addition of 2 equiv of [Cu(MeCN)(4)](BF(4)) to 2 led to CuCl and to the binuclear dicationic complex [Pt(2)Cl(2)(PONOP)(2)](BF(4))(2) (3), where chloro ligands have been substituted by pyridine groups. Conversely, reaction of 3 with chloride anions gave back complex 2. Solid-state (X-ray) and solution (NMR) studies indicated that after the transformation of 2 into 3, the platinum centers were brought much closer and the pyridinediphosphinite ligand was stiffened. The methylene NMR protons of 3 were strongly deshielded, and the corresponding proton-phosphorus coupling constants followed a Karplus-type relationship.

Journal Article↗
PubMed2001

Formation of a phosphorus-phosphorus bond by successive one-electron reductions of a two-phosphinines-containing macrocycle: crystal structures, EPR, and DFT investigations.

Chemical and electrochemical reductions of the macrocycle 1 lead to the formation of a radical monoanion anion [1](*)(-) whose structure has been studied by EPR in liquid and frozen solutions. In accord with experimental (31)P hyperfine tensors, DFT calculations indicate that, in this species, the unpaired electron is mainly localized in a bonding sigma P-P orbital. Clearly, a one-electron bond (2.763 A) was formed between two phosphorus atoms which, in the neutral molecule, were 3.256 A apart (crystal structure). A subsequent reduction of this radical anion gives rise to the dianion [1](2)(-) which could be crystallized by using, in the presence of cryptand, Na naphthalenide as a reductant agent. As shown by the crystal structure, in [1](2)(-), the two phosphinine moieties adopt a phosphacyclohexadienyl structure and are linked by a P-P bond whose length (2.305(2) A) is only slightly longer than a usual P-P bond. When the phosphinine moieties are not incorporated in a macrocycle, no formation of any one-electron P-P bond is observed: thus, one-electron reduction of 3 with Na naphthalenide leads to the EPR spectrum of the ion pair [3](*)(-) Na(+); however, at high concentration, these ion pairs dimerize, and, as shown by the crystal structure of [(3)(2)](2)(-)[(Na(THF)(2))(2)](2+) a P-P bond is formed (2.286(2) A) between two phosphinine rings which adopt a boat-type conformation, the whole edifice being stabilized by two carbon-sodium-phosphorus bridges.

Journal Article↗
PubMed1986

A survey of the phosphorus content of pastures and the serum inorganic phosphorus content of dairy cows.

Serum inorganic phosphorus (Pi) concentration of 20 cows in each of ten factory supply dairy herds was assessed at monthly or two-monthly intervals during the 198243 lactation. Pasture on offer was ranked low, medium or high and the phosphorus (P) content assessed monthly on all farms from the two paddocks to be grazed next in the rotation. The mean serum Pi concentration was high (1.98 mmol/l) prior to calving but fell to low levels at peak lactation (1.28 mmol/l) and again during the drought (1.28-1.38 mmol/l) in January, February and March. Individual cows had Pi levels as low as 0.32 mmol/l. Herds on Northern Yellow-brown Earths had higher Pi levels than herds predominantly on Brown Granular Loams (P<0.01). There were differences between cows within herds (P<0.01) and Pi levels declined with cow age (P<0.01). Pasture P content was above minimum requirements for lactating cows (0.33% DM; with ad lib. feeding) from July through October but below requirements in most pastures from December through April, when pasture availability also limited production. The P content in pasture was unrelated to either its grass or legume content, but was higher in pastures given a medium or high DM ranking (P<0.05). The possibility of increasing dairy production with P supplementation in spring is discussed.

Journal Article↗
PubMed1989

A survey of the phosphorus and calcium contents of pastures and the serum inorganic phosphorus and calcium contents of cows on four Manawatu dairy farms.

Serum inorganic phosphorus (Pi) and calcium (Ca) concentrations were assessed in 20 cows on each of four Manawatu factory supply dairy farms. Blood was taken from each cow before calving and at six-week intervals during lactation. Bleeding coincided with herd testing. Herds of Friesian or Friesian X cows and Jersey or Jersey X cows were compared on adjacent farms on a Central Yellow-brown Sand and on adjacent farms on a Peat Loam overlying a Central Yellow-brown Earth soil. Pasture mass and composition were estimated to grazing height in the next two paddocks to be grazed in the rotation. Mean serum Pi concentration was higher in cows on sandy soils (1.55 mmol Pi/l than in cows on the peat loam (1.34 mmol Pi/l (P<0.001). Concentrations were highest before calving (1.69 mmol Pi/l) but fell to low levels at peak lactation (1.17mmol Pi/l when 70% of cows were below the minima of the 'normal range', and during the drought (1.29 mmol Pi/l. Pasture phosphorus (P) concentrations were adequate to support cow nutrition for lactation (>0.33% DM, ad lib. feeding) until the summer drought when low herbage mass would have restricted milk production. Serum Ca was adequate for lactating cows and changed little between months or between cows (mean 2.12 mmol Ca/l). No metabolic disorders relating to mineral deficiencies were observed. It appears that serum Pi in a high proportion of cows falls below the normal range during peak lactation without cows displaying clinical deficiency symptoms or a depression in butterfat production.

Journal Article↗
PubMed1968

Effect of phosphorus deficiency on levels of phosphorus compounds in spirodela.

When Spirodela plants are transferred to a phosphate-deficient medium, growth slows down immediately, and ceases after 14 days. During this time, inorganic phosphate content falls from 30 to 0.7 mumoles/g fresh weight of tissue, phosphate ester content from 3.5 to 0.6 mumoles/g, phospholipid content from 3.5 to 1.2 mumoles/g, and residual phosphate (mainly RNA) content from 7.5 to 2.0 mumoles/g. Relative proportions of the various phosphate esters, and relative proportions of the various phospholipids, are not markedly affected by phosphate deficiency. Turnover rates of phosphate esters are somewhat higher in phosphate-deficient tissue. In control tissue, inorganic phosphate is present in 2 pools; a metabolic (12%) and a non-metabolic pool (88%). In phosphate-deficient tissues, most of the inorganic phosphate (>90%) is in the metabolic pool. Non-metabolic phosphate is presumably stored in the vacuole, and is not readily accessible to the tissue, so that growth normally occurs at the expense of external phosphate. During deficiency, growth is limited by the rate at which phosphate can be transported through the tonoplast and tissue to the growing point. Growth ceases when the supply of non-metabolic phosphate is exhausted. Metabolic phosphate is presumably located in the cytoplasm: it can not be used for growth. Nor can the plant respond to deficiency by making some phosphorus compounds at the expense of others. In this respect, phosphorus deficiency and nitrogen deficiency are dissimilar.

Journal Article↗
PubMed1978

Poisoning caused by inhalation of hydrogen chloride, phosphorus oxychloride, phosphorus pentachloride, oxalyl chloride, and oxalic acid.

Eleven people accidentally inhaled a significant amount of a gaseous mixture of hydrogen chloride, phosphorus oxychloride, phosphorus pentachloride, oxalyl chloride, and oxalic acid. Clinical observations and laboratory tests were recorded from the time of admission throughout hospitalization. The main abnormalities were found in the respiratory tract and consisted of clinical and physiologic evidence of obstruction of the airways, mild interstitial and alveolar edema, a defect in diffusion, and inequalities of ventilation and perfusion that produced hypoxemia. All of these cleared within a short time.

Accidents, Occupational↗
PubMed2005

Dissolved oxygen and dietary phosphorus modulate utilization and effluent partitioning of phosphorus in rainbow trout (Oncorhynchus mykiss) aquaculture.

Phosphorus (P) is the limiting nutrient in freshwater primary production, and excessive levels cause premature eutrophication. P levels in aquaculture effluents are now tightly regulated. Increasing our understanding of waste P partitioning into soluble, particulate, and settleable fractions is important in the management of effluent P. When water supply is limited, dissolved oxygen concentration (DO) decreases below the optimum levels. Therefore, we studied effects of DO (6 and 10mg/L) and dietary P (0.7 and 1.0% P) on rainbow trout growth, P utilization, and effluent P partitioning. Biomass increased by 40% after 3 weeks. DO at 10mg/L significantly increased fish growth and feed efficiency, and increased the amount of P in the soluble fraction of the effluent. Soluble effluent P was greater in fish fed 1.0% P. DO increases fish growth and modulates P partitioning in aquaculture effluent.

Animal Feed↗
PubMed2005

Effects of phosphorus intake on phosphorus flow in growing pigs: application and comparison of two models.

A comparison of the models of Vitti et al. (2000, J. Anim. Sci. 78, 2706-2712) and Fernández (1995c, Livest. Prod. Sci. 41, 255-261) was carried out using two data sets on growing pigs as input. The two models compared were based on similar basic principles, although their aims and calculations differed. The Vitti model employs the rate:state formalism and describes phosphorus (P) flow between four pools representing P content in gut, blood, bone and soft tissue in growing goats. The Fernández model describes flow and fractional recirculation between P pools in gut, blood and bone in growing pigs. The results from both models showed similar trends for P absorption from gut to blood and net retention in bone with increasing P intake, with the exception of the 65 kg results from Date Set 2 calculated using the Fernández model. Endogenous loss from blood back to gut increased faster with increasing P intake in the Fernández than in the Vitti model for Data Set 1. However, for Data Set 2, endogenous loss increased with increasing P intake using the Vitti model, but decreased when calculated using the Fernández model. Incorporation of P into bone was not influenced by intake in the Fernández model, while in the Vitti model there was an increasing trend. The Fernández model produced a pattern of decreasing resorption in bone with increasing P intake, with one of the data sets, which was not observed when using the Vitti model. The pigs maintained their P homeostasis in blood by regulation of P excretion in urine.

Animal Feed↗
PubMed2001

Long-term relationship between phosphorus inputs and wetland phosphorus concentrations in a northern Everglades marsh.

Assessments of long-term relationships between changes in nutrient inputs and wetland nutrient concentrations can be complicated by fluctuations in other environmental factors as well as by problems typical of long-term monitoring data. Consequently, statistical analysis of these types of data sets requires careful consideration of environmental covariates, potential biases in the monitoring design, and irregularities caused by changes in field sampling protocols. We evaluated the relationship between anthropogenic phosphorus (P) inputs and water-column total P (TP) concentrations in a northern Everglades marsh by statistically analyzing available data collected from several sampling programs over the past 20 years (1978-1997). Canal inputs of agricultural runoff contribute most of the P to the marsh and have produced a zone of enrichment within the marsh during the past few decades. Regression analyses showed that both canal and marsh TP concentrations increased during the 1980s and then decreased in the 1990s. However, the statistical relationship between canal P inputs and marsh TP, while significant, generally was weak except for marsh locations adjacent to the canal. Stronger relationships existed between marsh TP and hydrologic parameters such as marsh water depth, which is controlled by changes in weather patterns and marsh management. In particular, dry conditions during the 1980s may have contributed to observed increases in marsh P concentrations and the movement of a P 'front' further into the marsh. Higher rainfall and water depths and agricultural best management programs initiated during the 1990s have been associated with reduced P concentrations in canal waters entering the marsh. While it is anticipated that this reduction eventually will result in lower marsh TP concentrations, this effect is not yet evident, possibly due to internal loading of P from enriched marsh soils. Our findings illustrate some of the environmental factors that can complicate attempts to develop empirical relationships between P inputs and wetland P concentrations and to use such relationships to forecast changes in marsh concentrations based on past monitoring data alone.

Agriculture↗
PubMed2002

Use of the regression analysis technique to determine the true phosphorus digestibility and the endogenous phosphorus output associated with corn in growing pigs.

The objectives of this study were to determine true phosphorus (P) digestibility and the endogenous P output associated with corn for growing pigs using the regression analysis technique. Four barrows, average initial body weight of 25 kg, were fitted with a T-cannula and fed four diets according to a 4 x 4 Latin square design. Four cornstarch-based diets, containing four levels of P at 0.7, 1.5, 2.2 and 2.8 g/kg dry matter intake (DMI), were formulated from corn. Each experimental period comprised 8 d with 4-d adaptation and 4-d collection of ileal digesta and fecal samples. The apparent ileal and fecal P digestibility values in corn were affected (P < 0.05) by P contents in the assay diets. The apparent ileal and fecal P digestibility values increased from -51.0 to 33.3% and from -41.4 to 39.1%, respectively, as P content increased from 0.7 to 2.8 g/kg DMI. Linear relationships (P < 0.05), expressed as g/kg DMI, between the apparent ileal and fecal digestible P and the total intake of dietary P, suggested that true P digestibility and the endogenous P outputs associated with corn can be determined by the regression analysis technique. There were no differences (P > 0.05) in true P digestibility values (54.0 +/- 6.5 vs. 59.8 +/- 8.5%) and the endogenous P outputs (0.693 +/- 0.128 vs. 0.670 +/- 0.160 g/kg DMI) between the ileal and the fecal determinations. The endogenous fecal P output represented 12.3% and 25.8% of the daily total and available P requirements in growing pigs recommended by the National Research Council in 1998. The present literature data of apparent digestibility and availability underestimate the true digestive utilization of P in corn for growing pigs by approximately 35%. Current diet formulation on the bases of total, apparent P digestibility and availability values in corn inevitably leads to P overfeeding and excessive P excretion in pigs.

Animals↗
PubMed2000

Evaluation of normal yellow dent corn and high available phosphorus corn in combination with reduced dietary phosphorus and phytase supplementation for broilers grown to market weights in litter pens.

A study was conducted to determine the extent fecal P levels could be reduced while maintaining performance. Various strategies were employed including the use of a high available phosphorus hybrid of corn (HAPC), supplementation with phytase enzyme, and reduced dietary P levels. The use of HAPC resulted in a 50% reduction in phytate-bound dietary P as compared with a normal yellow dent corn (YDC) diet. Dietary nonphytate P was maintained at either NRC (1994) recommendations for appropriate age periods or reduced by 0.075 or 0.15%. Portions of the diets were supplemented with 1,000 units of phytase/kg. Male chicks of a commercial strain were grown to 56 d on the test diets. Broilers fed diets with HAPC had BW, feed conversion, livability, and tibia ash that were equal to or superior to those fed diets with YDC with considerably reduced fecal P content at any dietary level of nonphytate P. Phytase supplementation enabled birds to maintain live performance at lower levels of nonphytate P, further reducing the fecal P output. One of the greatest contributions of phytase was a reduction in mortality at the lower levels of nonphytate P. Dietary P levels could be reduced by 0.075% under NRC (1994) recommendations without adversely affecting live performance; a reduction of 0.15% in conjunction with phytase supplementation maintained BW, feed conversion, and livability but reduced tibia ash. The extent to which dietary P levels can be reduced over the entire feeding program is subject to further research.

6-Phytase↗
PubMed2006

Arbuscular mycorrhizal fungi contribute to phosphorus uptake by wheat grown in a phosphorus-fixing soil even in the absence of positive growth responses.

We used 32P to quantify the contribution of an arbuscular mycorrhizal (AM) fungus (Glomus intraradices) to phosphorus (P) uptake by wheat (Triticum aestivum), grown in compartmented pots. The soil was from a major cereal-growing area, the Eyre Peninsula, South Australia; it was highly calcareous and P-fixing. Fertilizer P was added to soil at 20 mg kg(-1), as solid or liquid. Two extraction methods were used to estimate plant-available P. Fungal colonization was well established at harvest (36 d). Application of P decreased both colonization and hyphal length density in soil, with small differences between different P fertilizers. Plants showed large positive responses in terms of growth or total P uptake to all P additions, and showed no positive (or even negative) responses to AM colonization, regardless of P application. 32P was detected only in AM plants, and we calculated that over 50% of P uptake by plants was absorbed via AM fungi, even when P was added. The results add to the growing body of knowledge that 'nonresponsive' AM plants have a functional AM pathway for P transfer to the plant; it should not be ignored in breeding plants for root traits designed to improve P uptake.

Mycorrhizae↗
PubMedDate not supplied

Wet chemical and phosphorus-31 nuclear magnetic resonance analysis of phosphorus speciation in a sandy soil receiving long-term fertilizer or animal manure applications.

In areas under intensive livestock farming and with high application rates of animal manure, inorganic and organic phosphorus (P) may be leached from soils. Since the contribution of these P compounds to P leaching may differ, it is important to determine the speciation of P in these soils. We determined the effect of various fertilization regimes on the P speciation in NaOH-Na2EDTA (ethylenediaminetetraacetic acid) and water extracts of acidic sandy soil samples from the top 5 cm of grassland with wet chemical analysis and 31P nuclear magnetic resonance (NMR) spectroscopy. These soils had been treated for a period of 11 years with no fertilizer (control), N (no P application), N-P-K, or different animal manures. Inorganic P was highly elevated in the NaOH-Na2EDTA extracts of the soils amended with N-P-K or animal manures, while organic P increased only in the soil treated with pig slurry. Water-extractable P showed a similar trend. As indicated by 31P NMR, orthophosphate monoesters were the main organic P compounds in all soils. Our results suggest that long-term applications of large amounts of P fertilizer and animal manures caused an accumulation of inorganic P, resulting in an increase of the potential risk related to mobilization of inorganic P in the top 5 cm of these soils.

Animals↗