scholarly journals Vitamin E catabolism in women, as modulated by food and by fat, studied using 2 deuterium-labeled α-tocopherols in a 3-phase, nonrandomized crossover study

2020 ◽  
Vol 113 (1) ◽  
pp. 92-103
Author(s):  
Maret G Traber ◽  
Scott W Leonard ◽  
Ifechukwude Ebenuwa ◽  
Pierre-Christian Violet ◽  
Mahtab Niyyati ◽  
...  
Keyword(s):  
Vitamin E ◽  
Crossover Study ◽  
Crossover Design ◽  
Intravenous Dose ◽  
Whole Body ◽  
Fecal Excretion ◽  
Liquid Meal ◽  
Healthy Women

ABSTRACT Background Human vitamin E (α-tocopherol) catabolism is a mechanism for regulating whole-body α-tocopherol. Objectives To determine the roles of the intestine and liver on α-tocopherol catabolism as affected by fat or fasting, 2 deuterium-labeled (intravenous d6- and oral d3-) forms of α-tocopherol were used. Methods Healthy women received intravenous d6-α-tocopherol and consumed d3-α-tocopherol with a 600-kcal defined liquid meal (DLM; 40% or 0% fat, n = 10) followed by controlled meals; or the 0% fat DLM (n = 7) followed by a 12-h fast (0% fat-fast), then controlled meals ≤72 h. The order of the 3-phase crossover design was not randomized and there was no blinding. Samples were analyzed by LC/MS to determine the α-tocopherol catabolites and α-carboxyethyl hydroxychromanol (α-CEHC) in urine, feces, and plasma that were catabolized from administered oral d3- and intravenous d6-α-tocopherols. Results Urinary and plasma d3- and d6-α-CEHC concentrations varied differently with the interventions. Mean ± SEM cumulative urinary d6-α-CEHC derived from the intravenous dose excreted over 72 h during the 40% fat (2.50 ± 0.37 μmol/g creatinine) and 0% fat (2.37 ± 0.37 μmol/g creatinine) interventions were similar, but a ∼50% decrease was observed during the 0% fat-fast (1.05 ± 0.39 μmol/g creatinine) intervention (compared with 0% fat, P = 0.0005). Cumulative urinary d3-α-CEHC excretion was not significantly changed by any intervention. Total urinary and fecal excretion of catabolites accounted for <5% of each of the administered doses. Conclusions Differential catabolism of the intravenous d6-α-tocopherol and oral d3-α-tocopherol doses shows both liver and intestine have roles in α-tocopherol catabolism. During the 40% fat intervention, >90% of urinary d3-α-CEHC excretion was estimated to be liver-derived, whereas during fasting <50% was from the liver with the remainder from the intestine, suggesting that there was increased intestinal α-tocopherol catabolism while d3-α-tocopherol was retained in the intestine in the absence of adequate fat/food for α-tocopherol absorption. This trial was registered at clinicaltrials.gov as NCT00862433.

scholarly journals Vitamin E absorption and kinetics in healthy women, as modulated by food and by fat, studied using 2 deuterium-labeled α-tocopherols in a 3-phase crossover design

2019 ◽  
Vol 110 (5) ◽  
pp. 1148-1167 ◽  
Author(s):  
Maret G Traber ◽  
Scott W Leonard ◽  
Ifechukwude Ebenuwa ◽  
Pierre-Christian Violet ◽  
Yu Wang ◽  
...  
Keyword(s):  
Vitamin E ◽  
Crossover Design ◽  
Pharmacokinetic Parameters ◽  
Apparent Effect ◽  
Blood Samples ◽  
Liquid Meal ◽  
Dual Isotope ◽  
Isotope Technique ◽  
Novel Approaches ◽  
Fractional Absorption

ABSTRACT Background Determining the human vitamin E [α-tocopherol (α-T)] requirement is difficult, and novel approaches to assess α-T absorption and trafficking are needed. Objective We hypothesized that the dual-isotope technique, using 2 deuterium-labeled [intravenous (IV) d6- and oral d3-] α-T, would be effective in determining α-T fractional absorption. Further, defined liquid meal (DLM) fat or fasting would modulate α-T fractional absorption and lipoprotein transport. Methods A 3-phase cr ossover design was used. At 0 h, participants received IV d6-α-T and consumed d3-α-T with a 600-kcal DLM (40% or 0% fat) followed by controlled meals or by the 0% fat DLM, a 12-h fast, and then controlled meals. Blood samples and fecal samples were collected at intervals and analyzed by LC-MS. Pharmacokinetic parameters were calculated from plasma tracer concentrations and enrichments. Fractional absorption was calculated from d3- to d6-α-T areas under the curve, from a novel mathematical model, and from the balance method (oral d3-α-T minus fecal d3-α-T excreted). Results Estimated α-T fractional absorption during the 40% fat intervention was 55% ± 3% (mean ± SEM; n = 10), which was 9% less than during the 0% fat intervention (64% ± 3%, n = 10; P < 0.02). Fasting had no apparent effect (56% ± 3%, n = 7), except it slowed plasma oral d3-α-T appearance. Both balance data and model outcomes confirmed that the DLM fat did not potentiate d3-α-T absorption. During the IV emulsion clearance, HDL rapidly acquired d6-α-T (21 ± 2 nmol/L plasma per minute). During the first 8 h postdosing, triglyceride-rich lipoproteins (TRLs) were preferentially d3-α-T enriched relative to LDL or HDL, showing the TRL precursor role. Conclusions Quantitatively, α-T absorption is not limited by fat absence or by fasting. However, α-T leaves the intestine by a process that is prolonged during fasting and potentiated by eating, suggesting that α-T absorption is highly dependent on chylomicron assembly processes. This trial was registered at clinicaltrials.gov as NCT00862433.

The Excretion of Isotope in Urea and Ammonia for Estimating Protein Turnover in Man with [15N]Glycine

1981 ◽  
Vol 61 (2) ◽  
pp. 217-228 ◽  
Author(s):  
E. B. Fern ◽  
P. J. Garlick ◽  
Margaret A. McNurlan ◽  
J. C. Waterlow
Keyword(s):  
Protein Metabolism ◽  
Protein Turnover ◽  
Mean Value ◽  
Intravenous Dose ◽  
Whole Body ◽  
Body Protein ◽  
End Products ◽  
The Mean ◽  
15N Urea ◽  
Normal Adults

1. Four normal adults were given [15N]-glycine in a single dose either orally or intravenously. Rates of whole-body protein turnover were estimated from the excretion of 15N in ammonia and in urea during the following 9 h. The rate derived from urea took account of the [15N]urea retained in body water. 2. In postabsorptive subjects the rates of protein synthesis given by ammonia were equal to those from urea, when the isotope was given orally, but lower when an intravenous dose was given. 3. In subjects receiving equal portions of food every 2 h rates of synthesis calculated from ammonia were much lower than those from urea whether an oral or intravenous isotope was given. Comparison of rates obtained during the post-absorptive and absorptive periods indicated regulation by food intake primarily of synthesis when measurements were made on urea, but regulation primarily of breakdown when measurements were made on ammonia. 4. These inconsistencies suggest that changes in protein metabolism might be assessed better by correlating results given by different end-products, and it is suggested that the mean value given by urea and ammonia will be useful for this purpose.

scholarly journals Effect of Clodronate Alone or In Combination with Vitamin E on Demineralization Induced By Whole Body Gamma Irradiation in Rats

2020 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Heba Gheita ◽  
Walaa Elsabbagh ◽  
Rania Abdelsalam ◽  
Amina Attia ◽  
Mona El-Ghazaly
Keyword(s):  
Vitamin E ◽  
Gamma Irradiation ◽  
Whole Body

Relation between pool size and catabolism of albumin in the mouse

1963 ◽  
Vol 204 (3) ◽  
pp. 501-504 ◽  
Author(s):  
Wallace Friedberg
Keyword(s):  
Immune Response ◽  
Human Serum Albumin ◽  
Saline Solution ◽  
Pool Size ◽  
Whole Body ◽  
Fecal Excretion ◽  
Absolute Rate ◽  
Fractional Rate ◽  
Equilibrium Level ◽  
Radioactivity Measurements

The catabolism of I131-labeled human serum albumin was investigated in mice in which the total albumin pool was increased with injections of massive amounts of human or mouse albumin. Control mice received the tracer albumin and saline solution. Daily whole-body radioactivity measurements were made on each animal over a period of several albumin half-lives. Since the absolute rate of albumin catabolism (mg/hr) is estimated by the product of the fractional rate (fraction of albumin pool/hr) and the pool size (mg of albumin), an unchanged or increased fractional rate concomitant with an increased pool size indicates a greater absolute rate of catabolism. A small increase in the fractional rate of albumin catabolism, unrelated to an immune response, occurred in the albumin-loaded mice. By inference, the equilibrium level of albumin in the serum is determined, in part, by a variable absolute rate of breakdown and this rate of breakdown is related to the total albumin pool size. Renal and fecal excretion of injected protein was insignificant.

Comparison of 24-Hour Whole Body versus Patch Tests for Estimating Body Surface Electrolyte Losses

2003 ◽  
Vol 13 (4) ◽  
pp. 479-488 ◽  
Author(s):  
Cristina Palacios ◽  
Karin Wigertz ◽  
Connie M. Weaver
Keyword(s):  
Surface Area ◽  
Body Surface Area ◽  
Body Surface ◽  
Whole Body ◽  
Patch Tests ◽  
Healthy Women ◽  
Electrolyte Content ◽  
Electrolyte Loss ◽  
Relative Comparisons

Purpose:To compare dermal electrolyte loss between whole body and regional patch methods in women during 24-h.Methods:Dermal loss was collected in 6 healthy women mean age 27 ± 4 years, while consuming 936 mg/d sodium, 1764 mg/d potassium, 696 mg/d calcium, and 152 mg/d magnesium. Twenty-four hour whole body dermal loss was collected using cotton suits by a washdown procedure. Twenty-four hour patch loss was collected from 8 patches placed on the legs, arms, and back.Results:Dermal loss from whole body was 108 ± 110 mg/d sodium, 133 ± 87 mg/d potassium, 103 ± 22 mg/d calcium, and 35 ± 13 mg/d magnesium. Electrolyte content from the 8 patches was similar among sites and ranged from 1.01–1.41 mg/d sodium, 0.35–0.83 mg/d potassium, 1.0– 1.45 mg/d calcium, and 0.43–0.49 mg/d magnesium. Projections from patches to whole body by the ratio of body surface area appear to overestimate actual whole body losses by 3.2X for sodium and calcium, 3.6X for magnesium, and 1.3X for potassium.Conclusions:Regional patch methods are more appropriate for relative comparisons than for accurately determining total daily dermal electrolyte losses.

Effects of Meals and Meal Times on Uptake of Lead from the Gastrointestinal Tract in Humans

1985 ◽  
Vol 4 (4) ◽  
pp. 401-407 ◽  
Author(s):  
H.M. James ◽  
M.E. Hilburn ◽  
J.A. Blair
Keyword(s):  
Dietary Habits ◽  
Whole Body ◽  
Turnover Rates ◽  
Lead Uptake ◽  
Liquid Meal ◽  
Whole Milk ◽  
Whole Body Counter ◽  
Phosphate Salts ◽  
Initial Uptake ◽  
Stimulation Of

1 Twenty three adults ingested 203Pb as lead acetate on the 12th hour of a 19 h fast. Retention measured 7 days later in a whole-body counter was 61% and whole-body turnover rates suggested that initial uptake had been considerably greater. 2 Balanced meals eaten with 203Pb reduced lead uptake to 4% and the influence of the food lasted for up to 3 h. The effects of phytate, ethylenediaminetetra acetate (EDTA), caffeine, alcohol, glucose, a liquid meal and a light snack were tested separately with intermediate results. 3 The effect of a meal was probably largely due to its content of calcium and phosphate salts but lead uptake was probably further reduced by phytate which is plentiful in whole cereals and it was probably increased by a factor in milk. Uptake with skimmed milk was the same as with whole milk and we suggested that the factor was not fat. Comestibles with low mineral and phytate contents reduced lead uptake by intermediate amounts, possibly by stimulation of digestive secretions. 4 The avid uptake of lead during a fast, the large reduction of lead uptake with meals and the likelihood of variations in gastric-emptying rates and dietary habits may be major causes of variation in body burdens of lead in the population.

Fish oil supplementation with and without added vitamin E differentially modulates plasma antioxidant concentrations in healthy women

Lipids ◽  
1998 ◽  
Vol 33 (12) ◽  
pp. 1163-1167 ◽  
Author(s):  
E. Turley ◽  
J. M. W. Wallace ◽  
W. S. Gilmore ◽  
J. J. Strain
Keyword(s):  
Vitamin E ◽  
Fish Oil ◽  
Healthy Women ◽  
Plasma Antioxidant ◽  
Fish Oil Supplementation
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