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1.
Nutrients ; 10(10)2018 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-30249044

RESUMO

Chronic kidney disease (CKD) affects approximately 10% of adults worldwide. Dysregulation of phosphorus homeostasis which occurs in CKD leads to development of CKD-Mineral Bone Disorder (CKD-MBD) and contributes to increased morbidity and mortality in these patients. Phosphorus is regulated by multiple hormones (parathyroid hormone (PTH), 1,25-dihyxdroxyvitamin D (1,25D), and fibroblast growth factor 23 (FGF23)) and tissues (kidney, intestine, parathyroid glands, and bone) to maintain homeostasis. In health, the kidneys are the major site of regulation for phosphorus homeostasis. However, as kidney function declines, the ability of the kidneys to adequately excrete phosphorus is reduced. The hormonal changes that occur with CKD would suggest that the intestine should compensate for impaired renal phosphorus excretion by reducing fractional intestinal phosphorus absorption. However, limited studies in CKD animal models and patients with CKD suggest that there may be a break in this homeostatic response where the intestine fails to compensate. As many existing therapies for phosphate management in CKD are aimed at reducing absolute intestinal phosphorus absorption, better understanding of the factors that influence fractional and absolute absorption, the mechanism by which intestinal phosphate absorption occurs, and how CKD modifies these is a much-needed area of study.


Assuntos
Absorção Intestinal , Intestinos/fisiologia , Rim/metabolismo , Síndromes de Malabsorção/etiologia , Fósforo na Dieta/metabolismo , Fósforo/metabolismo , Insuficiência Renal Crônica/complicações , Animais , Densidade Óssea , Doenças Ósseas/etiologia , Doenças Ósseas/metabolismo , Fatores de Crescimento de Fibroblastos/sangue , Homeostase , Humanos , Síndromes de Malabsorção/metabolismo , Hormônio Paratireóideo/sangue , Fósforo/farmacocinética , Fósforo na Dieta/farmacocinética , Insuficiência Renal Crônica/metabolismo , Vitamina D/análogos & derivados , Vitamina D/sangue
2.
Br J Nutr ; 119(12): 1346-1354, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29845902

RESUMO

To investigate the P absorption and gene expression levels of related co-transporters, type IIb sodium-dependent phosphate co-transporter (NaPi-IIb), inorganic phosphate transporter 1 (PiT-1) and inorganic phosphate transporter 2 (PiT-2) in the small intestine of broilers, 450 1-d-old Arbor Acres male broilers were randomly allocated to one of three treatments with ten replicate cages of fifteen birds per cage for each treatment in a completely randomised design. Chickens were fed a diet with no added inorganic P (containing 0·06 % non-phytate P (NPP)) or with either 0·21 or 0·44 % NPP for 21 d. Plasma P concentration in the hepatic portal vein, mRNA and protein expression levels of NaPi-IIb, PiT-1 and PiT-2 were determined at 7, 14 and 21 d of age. The results showed that the concentration of P in plasma in the hepatic portal vein increased as dietary NPP increased (P<0·0001). At 14 and 21 d of age, the increase in dietary NPP inhibited (P<0·003) NaPi-IIb mRNA expression level in the duodenum, as well as PiT-1 mRNA and protein expression levels in the ileum, but promoted NaPi-IIb protein expression level (P<0·002) and PiT-2 mRNA and protein expression levels (P<0·04) in the duodenum. These results suggest that NaPi-IIb, PiT-1 and PiT-2 might be important P transporters in the small intestine of broilers. Higher intestinal P absorption may be achieved by up-regulating the protein expression levels of NaPi-IIb and PiT-2 and down-regulating the protein expression of PiT-1.


Assuntos
Proteínas Aviárias/genética , Galinhas/genética , Galinhas/metabolismo , Intestino Delgado/metabolismo , Proteínas de Transporte de Fosfato/genética , Fósforo na Dieta/farmacocinética , Proteínas Cotransportadoras de Sódio-Fosfato Tipo IIb/genética , Ração Animal/análise , Animais , Proteínas Aviárias/metabolismo , Galinhas/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Absorção Intestinal/genética , Absorção Intestinal/fisiologia , Intestino Delgado/crescimento & desenvolvimento , Masculino , Proteínas de Transporte de Fosfato/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Cotransportadoras de Sódio-Fosfato Tipo IIb/metabolismo
3.
J Dairy Sci ; 101(8): 7208-7211, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29778467

RESUMO

The objective of the study was to evaluate the effect of inorganic phosphorus (Pi) infusion on P absorption in large intestine, milk production, and phosphorus excretion. Four ruminally and ileally cannulated crossbred cows were used in a 4 × 4 Latin square with 21-d periods. Cows were fed a total mixed ration containing 0.21% P, providing 50% of the cows' P requirement. Cobalt-EDTA was used as marker to measure large intestine digesta flow. On d 13 to 21 of each period, each cow was infused daily with 0, 20.1, 40.2, or 60.3 g of Pi into the abomasum and total collection was conducted on d 18 to 21. Ileal samples were collected every 9 h on d 18 to 21. Feed, digesta, and fecal samples were analyzed for total P and Pi using the molybdovanadate yellow method and blue method, respectively. All data were analyzed using PROC GLIMMIX in SAS 9.3 (SAS Institute Inc., Cary, NC) using contrasts to evaluate linear, quadratic, and cubic effects of Pi infusion dose. Dry matter intake, apparent dry matter digestibility, milk yield, and milk total P were unaffected by Pi infusion. Ileal flow and fecal excretion of total P and Pi increased linearly with increasing infused Pi. In the large intestine, net absorption of TP and Pi was increased linearly with increasing infused Pi. The magnitude of absorption from the large intestine was greater than reflected in current models, raising questions that could be evaluated with longer infusion periods or dietary alteration.


Assuntos
Abomaso/metabolismo , Bovinos/metabolismo , Absorção Intestinal/fisiologia , Leite/metabolismo , Fósforo na Dieta/farmacocinética , Animais , Dieta , Digestão , Feminino , Intestino Grosso/metabolismo , Lactação , Fósforo/metabolismo , Fósforo na Dieta/metabolismo , Rúmen
4.
J Environ Sci Health B ; 52(6): 395-401, 2017 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-28277077

RESUMO

A study was conducted to examine the effects of different dietary levels of available phosphorus (aP) on P excretion, bone mineralization, performance and the mRNA expression of sodium-dependent P transporters in growing pigs. Sixty-day old growing pigs (n = 54) with an average initial BW of 19.50 ± 1.11 kg were randomly allocated to a control diet (C) containing 0.23% available phosphorus (aP), T1 containing 0.17% aP and T2 containing 0.11% aP. There were 6 pens per treatment with 3 pigs per pen. Body weight and feed intake were measured weekly. At the end of each week, one pig from each pen was housed in a metabolic crate for 24 h to collect fecal and urine samples and then sacrificed to obtain third metacarpal (MC3) bones and jejunal and kidney samples. Bones were scanned by Dual Energy X-ray Absorptiometry (DEXA). Fecal and urine samples were sub-sampled and analyzed for P content. The expression of P transporter mRNA in jejunum and kidney samples was measured using quantitative real-time polymerase chain reaction (qRT-PCR). Data were analyzed using GLM procedure of the Statistical Analysis System (SAS Institute version 9.2). Pigs fed the T2 diet had reduced (P < 0.05) average daily gain (ADG) and gain to feed (G:F) compared to those fed the C diet during week 2. Overall, ADG and G:F were also reduced (P < 0.05) in pigs fed the T2 diet compared to those fed the C and T1 diets. Bone mineral density (BMD) and bone mineral content (BMC) were reduced (P < 0.05) in pigs fed the T2 diet compared to those fed the C diet throughout the experiment. At week 1, jejunal mRNA expression of Na (+)-dependent phosphate transporter 2 (SLC34A2) was increased (P < 0.01) in pigs fed the T2 diet compared to C diet. Renal mRNA expression of Na(+)-dependent phosphate transporter 1 (SLC34A1) and SLC34A3 were increased (P < 0.05) in pigs fed the T2 diet compared to those fed the C diet at week 2 and was accompanied by lower (P < 0.05) urinary P in pigs fed the T2 diet during week 2 and week 3. In conclusion, growing pigs are highly sensitive to low dietary P as shown by reduced ADG, bone mineralization and urinary P level, but moderate reduction in dietary P up to 0.17% aP in the diet has the potential to reduce environmental pollution by reducing P concentration in swine manure and without compromising performance.


Assuntos
Calcificação Fisiológica/efeitos dos fármacos , Fósforo na Dieta/farmacologia , Fósforo/farmacocinética , Proteínas Cotransportadoras de Sódio-Fosfato Tipo IIa/genética , Sus scrofa/crescimento & desenvolvimento , Absorciometria de Fóton , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Densidade Óssea , Fezes , Absorção Intestinal/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/metabolismo , Fósforo/metabolismo , Fósforo/urina , Fósforo na Dieta/farmacocinética , RNA Mensageiro , Reação em Cadeia da Polimerase em Tempo Real , Sus scrofa/metabolismo
5.
Nefrologia ; 37(1): 20-28, 2017.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27697413

RESUMO

Phytate, or myo-inositol 1,2,3,4,5,6-hexakis dihydrogen phosphate (InsP6), is a naturally occurring phosphorus compound that is present in many foods, mainly legumes, whole grains and nuts. Patients with chronic kidney disease (CKD) have cardiovascular disease mortality up to 30times higher than the general population. Vascular calcifications (VCs) directly contribute to overall morbidity and mortality, especially in CKD. In part, this high mortality is due to elevated levels of phosphorus in the blood. Therefore, control of dietary phosphorus is essential. Dietary phosphorus can be classified according to its structure in organic phosphorus (plant and animal) and inorganic (preservatives and additives). Plant-phosphorus (legumes and nuts), mainly associated with InsP6, is less absorbable by the human gastrointestinal tract as the bioavailability of phosphorous from plant-derived foods is very low. Recent data indicate that restriction of foods containing plant phosphates may compromise the adequate supply of nutrients that have a beneficial effect in preventing cardiovascular events, such as InsP6 or fibre found in legumes and nuts. Experimental studies in animals and observational studies in humans suggest that InsP6 can prevent lithiasis and VCs and protect from osteoporosis. In conclusion, we need prospective studies to elucidate the potential benefits and risks of phytate (InsP6) through the diet and as an intravenous drug in patients on haemodialysis.


Assuntos
Calcinose/prevenção & controle , Doenças Cardiovasculares/prevenção & controle , Hiperfosfatemia/complicações , Fosfatos/metabolismo , Fósforo na Dieta/farmacocinética , Ácido Fítico/metabolismo , Insuficiência Renal Crônica/metabolismo , Urolitíase/prevenção & controle , Animais , Antioxidantes/metabolismo , Arteriosclerose/prevenção & controle , Disponibilidade Biológica , Calcinose/etiologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/mortalidade , Distúrbio Mineral e Ósseo na Doença Renal Crônica/etiologia , Distúrbio Mineral e Ósseo na Doença Renal Crônica/prevenção & controle , Cinacalcete/uso terapêutico , Estudos Transversais , Fabaceae , Humanos , Hiperfosfatemia/mortalidade , Masculino , Estrutura Molecular , Nozes , Estudos Observacionais como Assunto , Osteoporose/tratamento farmacológico , Osteoporose/etiologia , Fósforo na Dieta/administração & dosagem , Fósforo na Dieta/efeitos adversos , Ácido Fítico/farmacologia , Ácido Fítico/uso terapêutico , Estudos Prospectivos , Ratos , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/dietoterapia , Urolitíase/etiologia
6.
J Ren Nutr ; 27(2): 78-83, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27810171

RESUMO

Phosphorus bioavailability is an emerging topic of interest in the field of renal nutrition that has important research and clinical implications. Estimates of phosphorus bioavailability, based on digestibility, indicate that bioavailability of phosphorus increases from plants to animals to food additives. In this commentary, we examined the proportion of dietary phosphorus from plants, animals, and food additives excreted in urine from four controlled-feeding studies conducted in healthy adults and patients with chronic kidney disease. As expected, a smaller proportion of phosphorus from plant foods was excreted in urine compared to animal foods. However, contrary to expectations, phosphorus from food additives appeared to be incompletely absorbed. The apparent discrepancy between digestibility of phosphorus additives and the proportion excreted in urine suggests a need for human balance studies to determine the bioavailability of different sources of phosphorus.


Assuntos
Queijo/análise , Dieta , Carne/análise , Fósforo na Dieta/urina , Plantas Comestíveis/química , Aditivos Alimentares/administração & dosagem , Humanos , Fósforo na Dieta/farmacocinética , Insuficiência Renal Crônica/urina
7.
J Ren Nutr ; 26(3): 136-40, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26873260

RESUMO

Dietary phosphorus restriction is recommended to help control hyperphosphatemia in hemodialysis patients, but many high-phosphorus foods are important sources of protein. In this review, we examine whether restricting dietary phosphorus compromises protein status in hemodialysis patients. Although dietary phosphorus and protein are highly correlated, phosphorus intakes can range up to 600 mg/day for a given energy and protein intake level. Furthermore, the collinearity of phosphorus and protein may be biased because the phosphorus burden of food depends on: (1) the presence of phosphate additives, (2) food preparation method, and (3) bioavailability of phosphorus, which are often unaccounted for in nutrition assessments. Ultimately, we argue that clinically relevant reductions in phosphorus intake can be made without limiting protein intake by avoiding phosphate additives in processed foods, using wet cooking methods such as boiling, and if needed, substituting high-phosphorus foods for nutritionally equivalent foods that are lower in bioavailable phosphorus.


Assuntos
Proteínas na Dieta/administração & dosagem , Hiperfosfatemia/prevenção & controle , Fósforo na Dieta/administração & dosagem , Fósforo na Dieta/efeitos adversos , Diálise Renal , Insuficiência Renal Crônica/terapia , Disponibilidade Biológica , Culinária/métodos , Aditivos Alimentares , Humanos , Avaliação Nutricional , Necessidades Nutricionais , Fosfatos , Fósforo na Dieta/farmacocinética
8.
Eur J Nutr ; 55(3): 991-6, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25953451

RESUMO

PURPOSE: High phosphorus content in the diet may have adverse effect on cardiovascular health. We investigated whether the New Nordic Diet (NND), based mainly on local, organic and less processed food and large amounts of fruit, vegetables, wholegrain and fish, versus an Average Danish Diet (ADD) would reduce the phosphorus load due to less phosphorus-containing food additives, animal protein and more plant-based proteins. METHODS: Phosphorus and creatinine were measured in plasma and urine at baseline, week 12 and week 26 in 132 centrally obese subjects with normal renal function as part of a post hoc analysis of data acquired from a 26-week controlled trial. We used the fractional phosphorus excretion as a measurement of phosphorus absorption. RESULTS: Mean baseline fractional phosphorus excretion was 20.9 ± 6.6 % in the NND group (n = 82) and 20.8 ± 5.5 % in the ADD group (n = 50) and was decreased by 2.8 ± 5.1 and 3.1 ± 5.4 %, respectively, (p = 0.6) at week 26. At week 26, the mean change in plasma phosphorus was 0.04 ± 0.12 mmol/L in the NND group and -0.03 ± 0.13 mmol/L in the ADD group (p = 0.001). Mean baseline phosphorus intake was 1950 ± 16 mg/10 MJ in the NND group and 1968 ± 22 mg/10 MJ in the ADD group and decreased less in the NND compared to the ADD (67 ± 36 mg/10 MJ and -266 ± 45 mg/day, respectively, p < 0.298). CONCLUSION: Contrary to expectations, the NND had a high phosphorus intake and did not decrease the fractional phosphorus excretion compared with ADD. Further modifications of the diet are needed in order to make this food concept beneficial regarding phosphorus absorption.


Assuntos
Dieta , Fósforo na Dieta/administração & dosagem , Fósforo na Dieta/farmacocinética , Adulto , Animais , Índice de Massa Corporal , Peso Corporal , Dinamarca , Proteínas na Dieta/administração & dosagem , Ingestão de Energia , Feminino , Peixes , Aditivos Alimentares/administração & dosagem , Aditivos Alimentares/análise , Aditivos Alimentares/farmacocinética , Frutas , Humanos , Masculino , Pessoa de Meia-Idade , Fósforo na Dieta/sangue , Fósforo na Dieta/urina , Alimentos Marinhos , Verduras , Grãos Integrais
9.
Eur J Nutr ; 55(8): 2445-2458, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26410393

RESUMO

INTRODUCTION: During growth, protein deprivation impairs epiphyseal growth plate (EGP) height, bone volume (BV) and endochondral ossification. During catch-up growth, Ca availability becomes essential to ensure the extra amount needed to achieve optimal peak bone mass and strength. GOS and FOS improve mineral absorption in the colon. PURPOSE: The effect of a mixture of GOS/FOS® 9:1 added to a 0.5 %Ca (NCa) and a 0.3 %Ca (LCa) diets on Ca, P and Mg absorptions and bone mineralization, density and structure using an experimental model of growing rats recovering from early protein malnutrition was investigated. METHODS: To induce protein malnutrition, rats were fed a low protein diet: 4 % (LPD) during 1 week and then were randomly assigned to recovery groups (R) until day 50 (T = 50) as follows: R0.5 %: NCa; RP0.5 %: NCa + 5.3 % GOS/FOS®; R0.3 %: LCa and RP0.3 %: LCa + 5.3 % GOS/FOS®. Control groups received the 0.5 %Ca or 0.3 %Ca diet from weaning until day 40 or 50. RESULTS: Body weight and length increased in C groups throughout the study; both were arrested in all R during LPD consumption and increased immediately after re-feeding. Independently of dietary Ca content, LS counts, ß-glucosidase and Ca, P and Mg absorption increased, whereas cecum pH, ß-glucuronidase, urease and tryptophanase decreased in RP0.5 %: and RP0.3 %: as compared to the other studied groups (p < 0.01). Prebiotic consumption decreased CTX levels and increased femur Ca, Mg and P contents, total skeleton bone mineral content, proximal tibia and spine BMD, BV, EGP height and hypertrophic zone thickness, stiffness and elastic modulus as compared to recovery groups fed the prebiotic-free diets. CONCLUSION: Under the present experimental conditions, GOS/FOS® mixture induced colonic positive effects, which increased Ca, P and Mg absorption. Thus, consuming the prebiotic-containing diet resulted in an extra amount of minerals that improved bone development in growing rats recovering from protein malnutrition.


Assuntos
Cálcio na Dieta/farmacocinética , Oligossacarídeos/administração & dosagem , Desnutrição Proteico-Calórica/tratamento farmacológico , Trissacarídeos/administração & dosagem , Animais , Disponibilidade Biológica , Peso Corporal , Densidade Óssea/efeitos dos fármacos , Desenvolvimento Ósseo/efeitos dos fármacos , Calcificação Fisiológica/efeitos dos fármacos , Cálcio na Dieta/administração & dosagem , Cálcio na Dieta/sangue , Ceco/efeitos dos fármacos , Ceco/metabolismo , Dieta , Fezes/química , Fêmur/efeitos dos fármacos , Fêmur/fisiologia , Glucuronidase/metabolismo , Lâmina de Crescimento/efeitos dos fármacos , Lâmina de Crescimento/fisiologia , Absorção Intestinal , Magnésio/administração & dosagem , Magnésio/sangue , Magnésio/farmacocinética , Masculino , Oligossacarídeos/sangue , Oligossacarídeos/farmacocinética , Fósforo na Dieta/administração & dosagem , Fósforo na Dieta/sangue , Fósforo na Dieta/farmacocinética , Prebióticos/administração & dosagem , Desnutrição Proteico-Calórica/sangue , Ratos , Ratos Wistar , Trissacarídeos/sangue , Trissacarídeos/farmacocinética , Triptofanase/metabolismo , Urease/metabolismo
10.
J Dairy Sci ; 99(2): 1237-1241, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26709165

RESUMO

The objective of the current work was to use digestion coefficients from the Feng et al. (2015) model (Virginia Tech model) to calculate P bioavailability of common feeds used in dairy production. Compared with the bioavailability calculated by the Virginia Tech model, using the NRC (2001) P absorption coefficient of 0.64 for forages would underestimate the bioavailabilities of alfalfa hay, alfalfa silage, corn silage, grass hay, and mixed mainly legume silage. For concentrates, using the NRC (2001) P absorption coefficient of 0.70 would overestimate the bioavailabilities of corn grain but underestimate bioavailability of high-moisture corn. Two dairy diets were formulated using nutrient values from the NRC (2001): a standard diet that includes minimal by-products, and a by-product diet that has reduced corn and soybean meal which was replaced with corn gluten feed, distillers grains, hominy feed, and wet brewers grains. For each diet, total bioavailable P was calculated using availability values from the NRC (2001) and the Virginia Tech model. Comparison of P balance (the difference between required and bioavailable P) for each diet was made using the 2 sets of bioavailabilities for a reference cow weighing 682 kg, producing 38.6 kg of milk/d (3.5% fat and 3.0% true protein, 100 d in milk), and consuming 23 kg of dry matter/d, yielding an absorbed P requirement of 59.4 g/d. The standard diet supplied 56.69 and 53.52 g of bioavailable P per day using bioavailabilities from the NRC (2001) and Virginia Tech models, respectively, resulting in a P balance of -2.71 and -5.88±0.26 g/d. The by-product diet provided 75.75 and 78.47 g/d of bioavailable P, yielding P balances of 16.35 and 19.07±0.37 g per day, respectively, using the 2 sets of bioavailabilities. Using P bioavailabilities for individual ingredients that were based on the Virginia Tech model resulted in different bioavailable P levels thus resulted in differing dietary P balances in a field setting.


Assuntos
Ração Animal , Bovinos/metabolismo , Fósforo na Dieta/farmacocinética , Animais , Disponibilidade Biológica , Indústria de Laticínios , Dieta/veterinária , Proteínas na Dieta , Digestão , Feminino , Glutens , Lactação/metabolismo , Medicago sativa , Modelos Biológicos , Silagem/análise , Virginia , Zea mays
11.
J Dairy Sci ; 98(8): 5385-400, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26026765

RESUMO

Hypophosphatemia is a common finding in periparturient and anorectic cattle. Although the clinical relevance of hypophosphatemia in cattle is uncertain, it has been empirically associated with persistent recumbency, specifically in periparturient dairy cows. The objective of the present study was to determine if transient dietary phosphorus (P) deprivation over a course of 5 wk, by feeding an approximately 40% P-deficient ration to lactating dairy cows, would result in altered muscle function or muscle P metabolism severe enough to present a risk for animal health and well-being. In addition, we wanted to determine the association between the plasma phosphate concentration ([Pi]) and muscle tissue P content to assess to what extent intracellular P deprivation of muscle cells could be extrapolated from subnormal plasma [Pi]. Ten healthy multiparous, mid-lactating dairy cows received a ration with a P content of 0.18% over a period of 5 wk. Following the P-deprivation phase, the same ration supplemented with P to obtain a dietary P content of 0.43% was fed for 2 wk. Blood and urine samples were collected regularly and muscle biopsies were obtained repeatedly to determine the P content in muscle tissue. Function of skeletal and heart muscles was evaluated by electrocardiography and electromyography conducted repeatedly throughout the study. Feeding the P-deficient ration resulted in the rapid development of marked hypophosphatemia. The lowest plasma [Pi] were measured after 9 d of P depletion and were, on average, 60% below predepletion values. Plasma [Pi] increased thereafter, despite ongoing dietary P depletion. None of the animals developed clinical signs commonly associated with hypophosphatemia or any other health issues. Urine analysis revealed increasing renal calcium, pyridinoline, and hydroxypyridinoline excretion with ongoing P deprivation. Biochemical muscle tissue analysis showed that dietary P depletion and hypophosphatemia were not associated with a decline in muscle tissue P content. Electromyographic examination revealed increased occurrence of pathological spontaneous activity in striated muscles after 2 wk of dietary P depletion in several cows, which could be suggestive of neuromuscular membrane instability. No effect on heart muscle activity was identified electrocardiographically. These results suggest that counter-regulatory mechanisms were sufficient to maintain normal muscle tissue P content during transient and moderate P deprivation. Muscle function was not grossly affected, although the increased occurrence of pathological spontaneous activity suggests that subclinical neuropathy or myopathy, or both, may have occurred with ongoing P deprivation. The results presented here indicate that plasma [Pi] is unsuitable for assessing muscle tissue P content in cattle.


Assuntos
Dieta/veterinária , Músculo Esquelético/fisiologia , Fósforo na Dieta/administração & dosagem , Fósforo na Dieta/farmacocinética , Aminoácidos/urina , Ração Animal/análise , Animais , Cálcio/urina , Bovinos , Suplementos Nutricionais , Feminino , Hipofosfatemia/sangue , Lactação , Músculo Esquelético/efeitos dos fármacos , Fosfatos/sangue , Fósforo/sangue , Fósforo/deficiência , Distribuição Tecidual
12.
Nutr Res Rev ; 28(1): 67-82, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26004147

RESUMO

There is increasing interest in dietary ingredients that are appropriate to support digestive and immune functions, but also maintain a stable microbial ecosystem in the gastrointestinal tract (GIT), particularly in weaned pigs. P is an essential nutrient for both microbes and their host, as it is involved, for example, in bone formation, energy metabolism, cellular signalling and stabilisation of cell membranes. Non-ruminant animals have limited access to phytate, the main storage form of P in plant seeds. The release of P bound to phytate requires phytase activity of plant or microbial origin, resulting in the formation of variable phosphorylated inositol phosphates (InsPs). The present review focuses on interactions between variations in dietary P supply, the immune system of the host, and the intestinal microbial ecosystem. Although results on the interaction between P and the immune system are inconsistent, several studies in different species have shown a positive impact of dietary P and phytase addition on the adaptive immune response. Recent studies with pigs suggest that P supply may influence intestinal microbial composition and activity. Individual InsPs or phosphate may also affect properties of pathogenic micro-organisms, such as metabolism or virulence. In conclusion, P may be considered as part of an integrated approach to support immune functions and maintain a stable microbial ecosystem in the GIT, thereby providing a barrier against potential pathogens. Within this regard, differences in phytate-P content and intrinsic phytase activity of plant feedstuffs, as well as the formation of individual InsPs, have to be taken into account.


Assuntos
Microbioma Gastrointestinal/efeitos dos fármacos , Sistema Imunitário/efeitos dos fármacos , Fósforo na Dieta/farmacologia , Suínos/imunologia , Suínos/microbiologia , 6-Fitase/administração & dosagem , Animais , Carboidratos da Dieta/administração & dosagem , Digestão , Nível de Saúde , Humanos , Hidrólise , Linfócitos/efeitos dos fármacos , Linfócitos/imunologia , Fagócitos/efeitos dos fármacos , Fagócitos/imunologia , Fósforo na Dieta/administração & dosagem , Fósforo na Dieta/farmacocinética , Ácido Fítico/administração & dosagem , Ácido Fítico/análise , Ácido Fítico/metabolismo , Plantas/química , Sementes/química
13.
J Anim Sci ; 93(5): 2174-82, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26020313

RESUMO

An experiment was conducted to determine the quantitative relationships between standardized total tract digestible P (STTD P) and total Ca intakes with their retention and excretion by growing pigs fed corn-soybean meal diets. Forty-eight crossbred barrows (BW = 22.7 ± 2.9 kg) were allotted to 1 of 8 diets, housed individually in pens for 3 wk, and then moved to metabolism crates and allowed 4 d for adaptation and 5 d for collection of urine and fecal samples. Eight corn-soybean meal diets were formulated for similar NE, fat, and AA concentrations but to increase the STTD P from 0.16 to 0.62% using monocalcium phosphate. Dietary treatments were formulated for a constant Ca:STTD P ratio (2.2:1). The STTD P intake increased (P < 0.001) from 64 to 242% of the daily requirement (4.59 g/d of STTD P). Fecal and total excretion of P and Ca were linearly associated with mineral intake (P < 0.001). Constant urinary P excretion of 0.03 g/d P was observed, but at 4.96 g/d of STTD P intake, the urinary P excretion increased (P < 0.001). In contrast, Ca excretion in urine decreased (P < 0.001) with Ca intake, but constant excretion of 0.40 g/d Ca was reached at 17.97 g/d of Ca intake. The daily intakes of STTD P and Ca moderately explained the variation in urinary excretion of P (R2= 0.41) and Ca (R2= 0.64). The absorption and retention of P increased linearly (P< 0.001) with dietary P intake, whereas absorption and retention of Ca showed a quadratic response (P < 0.001). Absorption and retention of P and Ca were highly predictable from the STTD P and Ca intakes, with of 0.87 and 0.90, respectively. The femur mineral content (FMC) increased by 2.71 g with STTD P intake (P < 0.001) but reached a plateau (29.54 g of FMC) at 8.84 g/d of STTD P intake. The FMC was highly predictable from the STTD P intake (R2 = 0.89). The FMC affected the urinary P excretion ( P< 0.01), but moderately (R2= 0.19) explained the variation in urinary P. In conclusion, constant excretion of P in urine was observed but excretion increased linearly at STTD P intake levels above the requirement for maximum growth of growing pigs. The FMC increased with STTD P intake, but a plateau was reached at a STTD P intake level above the requirement. Dietary STTD P was used for growth and accumulated in bones until a plateau was reached and excess was excreted in urine. The predictability of P and Ca excretion in urine from the dietary STTD P and Ca intakes was moderate.


Assuntos
Cálcio/farmacocinética , Trato Gastrointestinal/metabolismo , Fósforo na Dieta/farmacocinética , Suínos/metabolismo , Absorciometria de Fóton , Ração Animal/análise , Animais , Líquidos Corporais , Cálcio/metabolismo , Cálcio/urina , Calorimetria , Fezes/química , Fêmur/química , Alimentos Formulados , Absorção Gastrointestinal/fisiologia , Fósforo na Dieta/metabolismo , Fósforo na Dieta/urina , Soja/metabolismo , Zea mays/metabolismo
14.
J Dairy Sci ; 98(5): 3410-6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25771046

RESUMO

The effect of dietary P intake on intestinal P absorption was evaluated in growing Holstein steers. Diets varying in P content (0.15, 0.27, 0.36, and 0.45%, DM basis) were fed to 8 steers (174±10kg of BW) fitted with permanent duodenal and ileal cannulas in a replicated 4×4 Latin square with 14-d periods. Ytterbium-labeled corn silage and cobalt-EDTA were used as particulate and liquid phase markers, respectively, to measure digesta flow. Duodenal and ileal samples and spot urine samples were collected every 9 h from d 11 to 14. Total fecal collection was conducted on d 11 to 14 with fecal bags. Blood samples were collected from the coccygeal vessel on d 14. Feed, digesta, and fecal samples were analyzed for total P and inorganic P. Data were analyzed using PROC GLIMMIX in SAS with a model including treatment, square, period, and interaction of treatment and square. Preplanned contrasts were used to evaluate linear and quadratic treatment effects. Results were reported as least squares means. Dry matter intake (mean=4.90kg/d, 2.8% of BW) and apparent DM digestibility (mean=78.1%) were unaffected by treatment. Duodenal and ileal flow of total P increased linearly with increasing P intake (13.4, 18.5, 23.0, and 27.4g/d; 6.80, 7.87, 8.42, and 10.4g/d). Increasing P intake increased the quantity of P absorbed from the small intestine linearly (6.96, 11.1, 14.6, and 17.2g/d), but absorption efficiency was unchanged (mean=59.6%). Phosphorus was absorbed on a net basis from the large intestine, but this was not affected by treatment and was a small proportion of total P absorption. Blood inorganic P increased linearly with increased dietary P (4.36, 6.31, 7.68, and 8.5mg/dL) and salivary P secretion was unchanged (mean=5.79g/d), suggesting that rumen function was prioritized during short-term P deficiency. These data showing an absence of change in absorption efficiency and salivary P secretion in the face of short-term P deficiency may be used to improve published models of P digestion, absorption, and metabolism.


Assuntos
Absorção Intestinal/efeitos dos fármacos , Fósforo na Dieta/administração & dosagem , Fósforo na Dieta/farmacocinética , Animais , Beta vulgaris , Bovinos , Dieta/veterinária , Digestão , Duodeno/efeitos dos fármacos , Duodeno/metabolismo , Fezes/química , Íleo/efeitos dos fármacos , Íleo/metabolismo , Masculino , Fósforo/sangue , Fósforo/urina , Rúmen/efeitos dos fármacos , Rúmen/metabolismo , Silagem , Zea mays
15.
J Anim Sci ; 93(1): 158-67, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25568364

RESUMO

Two comparative serial-slaughter experiments were conducted to determine whole empty body (WEB) composition and accretion rates of Ca and P in 18 to 109 kg BW pigs to provide information for modeling of these nutrients for growth. Both studies were conducted with 5 sets of 5 littermate barrows which were allotted to 5 slaughter groups in each study (Exp. 1: 18, 27, 36, 45, and 54 kg BW; Exp. 2: 36, 54, 73, 91, and 109 kg BW). Pigs were fed corn-soybean meal-based diets fortified with minerals and vitamins in 2 dietary phases in Exp. 1 (Phase 1: 18 to 36 kg BW; Phase 2: 36 to 54 kg BW) and 3 dietary phases in Exp. 2 (Phase 2: 36 to 54 kg BW; Phase 3: 54 to 78 kg BW; and Phase 4: 78 to 109 kg BW). At the predetermined BW, pigs were slaughtered and separated into body components of hair, hooves, blood, head, viscera, and carcass. The carcass was split along the dorsal midline and the left carcass side was ground for chemical analysis. Whole empty body weight averaged 93.6% and 94.0% of live BW in Exp. 1 and Exp. 2, respectively. As WEB weight increased in both experiments, the percentage carcass of the WEB linearly (P < 0.05) increased, the percentage viscera linearly (P < 0.05) decreased, and the mass (g) of N, ash, Ca, and P in the WEB increased linearly (R(2) = 0.98). The concentration (g/kg) of P in the WEB of 18 to 54 kg pigs increased from 4.30 to 4.57 (linear; P < 0.05) and for Ca increased from 5.13 to 5.66 (linear; P < 0.05). In Exp. 2, P concentration was not related to WEB weight and Ca concentration increased quadratically (P < 0.05). The relative accretion rate of N to P was 1.00 (R(2) = 0.99) in the pigs from 18 to 54 kg. In conclusion, these results indicate that compositional changes as BW increases are strongly related to P retention and that the quantification of WEB P and relationships of WEB P to other chemical components in the body may be useful for modeling purposes in growing and finishing pigs.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Composição Corporal/fisiologia , Cálcio na Dieta/farmacocinética , Fósforo na Dieta/farmacocinética , Sus scrofa/crescimento & desenvolvimento , Sus scrofa/metabolismo , Ração Animal/análise , Criação de Animais Domésticos/métodos , Animais , Peso Corporal/fisiologia , Modelos Biológicos , Suínos
16.
Nephrol Ther ; 10(6): 441-50, 2014 Nov.
Artigo em Francês | MEDLINE | ID: mdl-25070605

RESUMO

The number of patients with chronic kidney disease (CKD) with its associated complications has increased dramatically worldwide in recent years. Therefore, many experimental and clinical studies have examined over the last decade the mechanisms involved, in order to explain the sharp increase in cardiovascular mortality. Hyperphosphatemia is a major problem in these patients especially at advanced stages of CKD, and it is associated with cardiovascular and mineral complications in these patients. Sevelamer is a phosphate binder that allows a better control of hyperphosphatemia, like other phosphate binder agents, but it has additional pleiotropic effects such as correcting certain abnormalities of lipid metabolism and clearance of several uremic toxins. These effects of sevelamer, restricted to the intestinal lumen, underline the importance of intestinal pathway in CKD and open the way to new therapeutic strategies for the management of the CKD and its complications.


Assuntos
Quelantes/farmacologia , Fósforo na Dieta/farmacocinética , Fósforo , Sevelamer/farmacologia , Animais , Remodelação Óssea/efeitos dos fármacos , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Quelantes/uso terapêutico , Terapia por Quelação , Modelos Animais de Doenças , Endotélio Vascular/efeitos dos fármacos , Produtos Finais de Glicação Avançada/metabolismo , Humanos , Hiperfosfatemia/tratamento farmacológico , Hiperfosfatemia/etiologia , Hiperfosfatemia/metabolismo , Inflamação/tratamento farmacológico , Absorção Intestinal/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos , Ensaios Clínicos Controlados Aleatórios como Assunto , Diálise Renal/efeitos adversos , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/terapia , Sevelamer/uso terapêutico , Toxinas Biológicas/metabolismo , Uremia/metabolismo , Ácido Úrico/metabolismo
17.
J Radiol Prot ; 34(2): 417-33, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24893947

RESUMO

This paper reviews data related to the biokinetics of phosphorus in the human body and proposes a biokinetic model for systemic phosphorus for use in updated International Commission on Radiological Protection (ICRP) guidance on occupational intake of radionuclides. Compared with the ICRP's current occupational model for systemic phosphorus (Publication 68, 1994), the proposed model provides a more realistic description of the paths of movement of phosphorus in the body and greater consistency with experimental, medical, and environmental data regarding its time-dependent distribution. For acute uptake of (32)P to blood, the proposed model yields roughly a 50% decrease in dose estimates for bone surface and red marrow and a six-fold increase in estimates for liver and kidney compared with the model of Publication 68. For acute uptake of (33)P to blood, the proposed model yields roughly a 50% increase in dose estimates for bone surface and red marrow and a seven-fold increase in estimates for liver and kidney compared with the model of Publication 68.


Assuntos
Modelos Biológicos , Radioisótopos de Fósforo/sangue , Radioisótopos de Fósforo/farmacocinética , Fósforo na Dieta/sangue , Fósforo na Dieta/farmacocinética , Contagem Corporal Total/métodos , Adulto , Simulação por Computador , Feminino , Humanos , Masculino , Taxa de Depuração Metabólica , Especificidade de Órgãos/fisiologia , Doses de Radiação , Distribuição Tecidual
18.
J Anim Sci ; 92(8): 3407-15, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24948654

RESUMO

The objective of this experiment was to measure the apparent total tract digestibility (ATTD) and the retention rate of Zn, Cu, Mn, and Fe in pigs fed either inorganic or organic sources of Zn, Cu, Mn, and Fe. The experimental design was a randomized complete block design with a 2 × 3 factorial arrangement of treatments. There were 2 types of diets (corn grits-based or corn-soybean meal [SBM]-based diets) and 3 micromineral treatments (basal micromineral premix [BMM], inorganic micromineral premix [IMM], and organic micromineral premix [OMM]). The BMM contained no added Zn, Cu, Mn, or Fe; the IMM microminerals were provided as sulfates of Zn, Cu, Mn, and Fe at 40, 50, 20, and 100 mg/kg, respectively. The OMM contained the same levels of the 4 microminerals as IMM, but Zn, Cu, Mn, and Fe in this premix were provided by Zn(2-hydroxy-4-methylthio butanoic acid [HMTBa])2, Cu(HMTBa)2, Mn(HMTBa)2, and FeGly, respectively. Forty-eight barrows (initial BW: 31.1 ± 4.2 kg) were housed individually and allowed ad libitum access to the corn grits diet with BMM for 2 wk. All pigs were then moved to metabolism cages and randomly assigned to 1 of the 6 treatment diets with 8 replicates per diet. Fecal and urine samples were collected for 5 d following a 5-d adaptation period. Compared with corn grits diets, pigs fed corn-SBM diets had greater (P < 0.05) absorption and retention of Zn, Cu, and Mn but less (P < 0.05) ATTD of Zn and Cu. Compared with BMM, supplementation of IMM or OMM increased (P < 0.05) absorption, retention, ATTD, and retention rate of Zn, Cu, Mn, and Fe. Compared with IMM, adding OMM to the corn-SBM diet improved (P < 0.05) the absorption and retention of Cu and Mn and the ATTD of Cu, but these differences were not observed in the corn grits diets (interaction, P < 0.05). In addition, adding OMM to the corn-SBM diet increased (P < 0.05) absorption and retention of Zn and Fe and ATTD of Zn, Mn, and Fe compared with adding IMM to the corn-SBM diet. Supplementation of OMM also increased (P < 0.05) the ATTD and retention rate of P in corn-SBM diets. Results indicate that Zn(HMTBa)2 has greater digestibility and Cu(HMTBa)2 and Mn(HMTBa)2 have greater digestibility and retention rates compared with their inorganic sulfates, if included in a corn-SBM diet. Supplementation of organic microminerals also improves the digestibility of P in a corn-SBM diet.


Assuntos
Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Dieta/veterinária , Digestão/fisiologia , Sus scrofa/metabolismo , Sus scrofa/fisiologia , Animais , Cálcio na Dieta/farmacocinética , Cobre/farmacocinética , Dieta/métodos , Suplementos Nutricionais , Fezes/química , Ferro/farmacocinética , Manganês/farmacocinética , Minerais/metabolismo , Fósforo na Dieta/farmacocinética , Soja/metabolismo , Suínos , Zea mays/metabolismo , Zinco/farmacocinética
19.
Acta Sci Pol Technol Aliment ; 13(1): 43-54, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24583383

RESUMO

BACKGROUND: Bread can be a good source of nutrients as well as non-nutrient compounds. This study was designed to assess the effect of adding of sourdough and whey proteins to wholemeal (WM) bread produced by bake-off technology on chemical composition and bioavailability of proteins, calcium, phosphorus, magnesium and iron content in Wistar rats. MATERIAL AND METHODS: Wholemeal breads were baked with using conventional or bake off technology. In breads chemical composition, selected minerals content, amino acid composition were measured. Five week-old Wistar rats (n = 30, male), were randomly divided into fi ve groups and fed with modified AIN-93G diets containing experimental breads. In animal study the nutritional value of breads' proteins and concentration of selected minerals in serum, liver and femoral bone, were measured. RESULTS: The body weight gain, biological value (BV) and net protein utilization (NPU) were significantly higher in rats fed with partially baked frozen wholemeal (PBF WM) bread with sourdough and whey proteins. The level of magnesium was significantly lower in serum of animals fed with the diet containing PBF WM bread with sourdough and whey proteins in comparison to rodents fed with conventional WM bread with sourdough. The content of iron was significantly higher in liver of rats fed with PBF WM with sourdough bread in comparison to the groups fed with conventional WM and conventional WM with sourdough breads. CONCLUSIONS: Sourdough addition can be recommended in a production of whole wheat partially baked frozen bread but its use is further more beneficial if it is fermented with whey proteins.


Assuntos
Pão/análise , Qualidade dos Alimentos , Alimentos Fortificados/análise , Proteínas do Leite/análise , Triticum/química , Animais , Disponibilidade Biológica , Cálcio na Dieta/administração & dosagem , Cálcio na Dieta/farmacocinética , Dieta , Proteínas na Dieta/administração & dosagem , Proteínas na Dieta/farmacocinética , Fermentação , Farinha/análise , Manipulação de Alimentos , Ferro na Dieta/administração & dosagem , Ferro na Dieta/farmacocinética , Magnésio/administração & dosagem , Magnésio/farmacocinética , Masculino , Fósforo na Dieta/administração & dosagem , Fósforo na Dieta/farmacocinética , Ratos , Ratos Wistar , Proteínas do Soro do Leite
20.
J Dairy Sci ; 97(1): 411-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24210479

RESUMO

Accurate estimates of phosphorus (P) availability from feed are needed to allow P requirements to be met with reduced P intake, thus reducing P excretion by livestock. Exogenous phytase supplementation in poultry and swine diets improves bioavailability of P, and limited research suggests that this strategy may have some application in dairy cattle rations. The effects of exogenous phytase and forage particle length on site and extent of P digestion were evaluated with 5 ruminally and ileally cannulated lactating cows (188 ± 35 d in milk). Cows were assigned in a 2 × 2 factorial arrangement of treatments in 2 incomplete Latin squares with four 21-d periods. Diets contained P slightly in excess of National Research Council requirements with all P from feed sources. During the last 4d of each period, total mixed ration, refusals, omasal, ileal, and fecal samples were collected and analyzed for total P, inorganic P (Pi), and phytate (Pp). Total P intake was not influenced by dietary treatments but Pp intake decreased and Pi intake increased with supplemental phytase, suggesting rapid action of the enzyme in the total mixed ration after mixing. Omasal flow of Pi decreased with phytase supplementation, but we observed no effect of diet in ileal flow or small intestinal digestibility of any P fraction. Fecal excretion of total P was slightly higher and Pp excretion was lower for cows receiving diets supplemented with phytase. Milk yield and composition were unaffected by diets. When phytase was added to the mixed ration, dietary Pp was rapidly degraded before intake and total-tract Pp digestion was increased. The lack of effect of phytase supplementation on dietary P utilization was probably because these late-lactation cows had a low P requirement and were fed P-adequate diets.


Assuntos
6-Fitase/administração & dosagem , Dieta/veterinária , Digestão , Lactação , Fósforo na Dieta/administração & dosagem , Fósforo na Dieta/farmacocinética , Animais , Bovinos , Suplementos Nutricionais , Feminino , Leite/química , Omaso/metabolismo , Ácido Fítico/administração & dosagem
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