Threonine utilization is high in the intestine of piglets

The whole-body threonine requirement in parenterally fed piglets is substantially lower than that in enterally fed piglets, indicating that enteral nutrition induces intestinal processes in demand of threonine. We hypothesized that the percentage of threonine utilization for oxidation and intestinal protein synthesis by the portal-drained viscera (PDV) increases when dietary protein intake is reduced. Piglets (n = 18) received isocaloric normal or protein-restricted diets. After 7 h of enteral feeding, total threonine utilization, incorporation into intestinal tissue, and oxidation by the PDV, were determined with stable isotope methodology [U-(13)C threonine infusion]. Although the absolute amount of systemic and dietary threonine utilized by the PDV was reduced in protein-restricted piglets, the percentage of dietary threonine intake utilized by the PDV did not differ between groups (normal protein 91% vs. low protein 85%). The incorporation of dietary threonine into the proximal jejunum was significantly different compared with the other intestinal segments. Dietary, rather than systemic threonine was preferentially utilized for protein synthesis in the small intestinal mucosa in piglets that consumed the normal protein diet (P < 0.05). Threonine oxidation by the PDV was limited during normal protein feeding. In protein-restricted pigs, half of the total whole-body oxidation occurred in the PDV. We conclude that, in vivo, the PDV have a high obligatory visceral requirement for threonine. The high rate of intestinal threonine utilization is due mainly to incorporation into mucosal protein

ETUDE DE LA SYNTHESE PROTEIQUE INTESTINALE A L'AIDE D'ISOTOPES STABLES CHEZ L'HOMME

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Net energy value of two low-digestible carbohydrates, Lycasin®HBC and the hydrogenated polysaccharide fraction of Lycasin®HBC in healthy human subjects and their impact on nutrient digestive utilization

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Validation de l'impédancemétrie bi-fréquence lors de la sclérose latérale amyotrophique.

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Comparison of the postprandial chylomicron carotenoid responses in young and older subjects

International audienceBackground:. The plant carotenoids may contribute to the beneficial health effect of fruits- and vegetables-rich diet. Epidemiological studies consistently associated high plasma carotenoids status with reduced age-related diseases. However, the data concerning the bioavailability of carotenoids in the elderly are scarce. Objective:. To test whether there is an age effect on carotenoid bioavailability. Design:. Eight young (20-35 y) and eight older (60-75 y) healthy adults ingested three different meals containing 40 g triacylglycerols (TG) and vegetable sources of carotenoids. These sources were either 188 g carrot puree which provided 30 mg betacarotene as the main carotenoid, or 61 g tomato puree providing 30mg lycopene, or 260 g cooked chopped spinach providing 30 mg lutein. TG and carotenoids were assayed in chylomicrons (CM) collected for 9 h postprandially. Results:. There was no major effect of age on the postprandial CM/TG response (0-9 h area under the curve (AUC)). There was no major effect of age on the postprandial CM all-trans beta-carotene, cis betacarotene, alpha-carotene, and lutein responses.Adjustment of these responses by the CM TG responses did not reveal any age effect. While there was no significant effect of age on the CM lycopene response, the CM TG-adjusted lycopene response was significantly lower (-40 %) in the older than in the younger subjects (P < 0.04). The cis-trans ratios of CM betacarotene were not significantly different between the old and the young subjects. There was no significant effect of age on the ratio of CM retinyl-palmitate to the sum of alpha-carotene and beta-carotene measured after the carrot meal. Conclusions:. The bioavailability of lycopene is apparently impaired in the old,while there is no major difference in the bioavailability of beta-carotene, alpha-carotene and probably lutein. There is also no major effect of age on the cis-trans isomerization of beta-carotene during absorption, and in the intestinal conversion of provitamin A carotenoids into vitamin A

Processing of vegetable-borne carotenoids in the human stomach and duodenum

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La capacité du muscle à oxyder les acides gras varie selon l'activité physique des personnes âgées et influence l'oxydation des lipides dans le corps entier

Le gain de masse grasse observ6 au cours du vieillissement pourrait s'expliquer par une diminution de l'oxydation des lip[des dens le corps antler. Ces modifications pourraient ~tre dues au moths en partie b. une diminution de la capEt[t6 du muscle b. oxyder les at[des gras (AG) en relation avec la sddenterisation des personnes. Le but de l'&ude est done d'analyser les variations de la eapacit6 du muscle b. oxyder les AG salon I'aetivit6 physique habituelle et les consdquences sur I'oxydation des lip[des dens le corps entier chez des personnes ,~gdes (65±4 ans), sddentaires (n=l 1) ou entra~ndes an endurance (n=7). Les sujets net &6 earact~risds par lanr consommation max[male d'oxyg~ne (VO2~) et par leur niveau d'aetivit6 physique moyen (NAP, ddtermin6 ~t perfir de l'enregistrement de la fr~quenee eardiaque sur 3 jours). La capaeit6 du muscle ~i oxyder in vitro du [IA~C] palm[tare a 616 mesurde sur des biopsies provenant du vesta exteran (Veerkamp et al. Biochem Biophys Aeta 1983, 753 : 399-410). L'oxydation des lip[des dens le corps antler a &6 mesurde par ealorimdtrie indireete sur 24h. Les rdsultats ont 6t6 ajustds pour les diff&enees de VO2~ et de balance 6nergdtique avant d'&udier les relations avec la capacit6 oxydative museulaire. La capacit6 oxydative museulaire est corrdlde au NAP (r=0,58, P<0,05), rnais pas ~t la VOz~ (r=0,35, P=NS). Apr%s ajustemant pour les diffdrences de VO2m~ et de balance 6nergdtique, l'oxydation des lip[des dens le corps antler est eorrdlde ~t la capacit6 oxydative musculaire pendant la pdriode 6veillde (r=0,59, P=0,008) et sur 24h (r=0,54, P=-0,02), mats pas pendant le sommeil (~0,04, P=-NS). En conclusion, la eapaeit6 du muscle ~ oxydar les AG est un ddterminant de I'oxydation des lip[des dans le corps antler pendant la pdriode 6veillde, et par eousdquent sur 24h. Ainsi, un ddfant daus la eapanit6 oxydative museulaire assoei6 ~ de falbles eapacit~s eerdiovasculaires, en raison d'un mode de vie sddentaire, pourraient expliquer una diminution de l'oxydation des lip[des daus le corps antler

Influence of short-chain fructo-oligosaccharides (sc-FOS) on absorption of Cu, Zn, and Se in healthy postmenopausal women

International audienceOBJECTIVE: This study was carried out to evaluate the effect of short-chain fructooligosaccharides (sc-FOS) on the absorption of Cu, Zn, and Se among postmenopausal women who are potential candidates to subclinical trace element deficiencies. DESIGN: A randomized double blind cross-over study. SETTING: This study was carried out at the Human Nutrition Research Center, Clermont-Ferrand, France. SUBJECTS: 11 postmenopausal women aged 53-70 y, not taking hormone replacement therapy were enrolled and completed the study. INTERVENTIONS: Diets with 10 g/day sc-FOS or placebo were given for 5 weeks each in random order followed by a wash-out period of at least 3 weeks. At the end of each period, stable isotopes (3.19 mg 67Zn as ZnCl2, 2.06 mg 65Cu as CuCl2 and 52.3 microg 74Se as sodium selenite) and radiopaque pellets (as fecal excretion index) were administered during lunch. Stools were collected for the next 5-7 days. Isotopes were determined by ICP-MS (Cu and Zn) or GC-MS (Se). RESULTS: Copper absorption was significantly enhanced (p = 0.042) by sc-FOS. No effect of sc-FOS was observed on Zn, and Se absorption. CONCLUSION: To our knowledge, this is the first study on the influence of sc-FOS on trace element metabolism. The observed increase in copper absorption may be of interest regarding daily copper requirements in menopausal women. However, the relevance of this observation remains to be established

Influence of organic versus conventional agricultural practice on the antioxidant microconstituent content of tomatoes and derived purees; consequences on antioxidant plasma status in humans

DOI: 10.1021/jf0346861International audienc