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The incidence of type 2 diabetes is considered an epidemic in Western countries, and its prevalence is more common in the Hispanic population than in non-Hispanic whites. Postprandial hyperglycemia has been associated with oxidative stress (OS), thus; reducing postprandial glycemia and/or OS through dietary consumption of resistant starch (RS) may be one approach to help modulate glucose and insulin responses. The purpose of this study was twofold: 1) to evaluate the physicochemical and sensory properties of cereal food products supplemented with RS. 2) to compare the effects of a single ingestion of granola bars with high (~18 grams of RS) and low (~0 grams of RS) RS compositions on the postprandial glucose and insulin responses (n=14) and oxidative stress parameters (cellular glutathione peroxidase, F2- isoprostanes, and oxygen radical absorbance capacity) in Hispanic women (n=9). Granola bars and cereals were developed to provide 2 levels (10% and 15%) of RS; isocaloric (0% RS) control samples were prepared with readily digestible (high amylopectin) starch. Samples were stored for up to 4 weeks at 20 °C. Mean composition of the high RS granola bars was 6% protein, 15% moisture, and 18% lipid. RS levels slightly increased from 14 to 16 g/serving after 4 weeks of storage, supporting published research that RS increases with storage due to retrogradation and crystallization of amylose chains. Color became lighter as the level of RS increased (p<0.001). Granola bars containing RS were less brittle (p=0.0043) than control granola bars. Sensory results indicated granola bars/cereals were acceptable. RS-supplemented granola bars were then used for the evaluation of RS ingestion in humans. There was no difference in postprandial glucose and insulin responses after a single ingestion of a RS-supplemented (18 g) granola bar. No differences were found in the oxidative stress parameters measured. In a subgroup of subjects (n=9), a lower glucose response 30 minutes after RS consumption was found (p=0.0496). Thus, RS consumption may lower fluctuations in blood glucose, which may help manage glucose levels in individuals at risk of type 2 diabetes. Further studies of short term RS consumption are warranted to elucidate its benefits in glucose management. / Ph. D.

Elevated postprandial triacylglycerol concentrations ([TAG]) are associated with the development and progression of atherosclerosis, and are established as an independent risk factor for future cardiovascular disease. Considering the majority of the daytime is spent in a postprandial state typically, and the paediatric origins of atherosclerosis are well established, lifestyle interventions including manipulations of exercise energy expenditure and dietary energy intake should be initiated early in life. Therefore, this thesis aimed to investigate the postprandial metabolic responses to different exercise and energy intake manipulations in boys and girls, with concentrations of circulating TAG representing the primary outcome of interest. To achieve this, a total of 60 healthy 11 to 13 year old boys and girls were recruited into five experimental studies. The first experimental study (Chapter 4) demonstrated that a single session of high-intensity interval running (HIIR) involving 10 x 1 min intervals at 100% maximal aerobic speed (MAS) resulted in a moderate reduction in postprandial plasma [TAG] in 11 to 12 year old boys. In the second experimental study (Chapter 5), immediate replacement of the moderate-intensity exercise-induced energy deficit negated the reduction in postprandial plasma [TAG] in 11 to 13 year old boys. Furthermore, an exercise-induced energy deficit was required to promote an increase in whole-body fat oxidation. The importance of the associated energy deficit was explored further in Chapter 6, which demonstrated that a moderate-intensity exercise-induced energy deficit elicited a greater reduction in postprandial plasma [TAG] than an isoenergetic diet-induced energy deficit in 11 to 13 year old girls (21% vs. 10% respectively). Chapter 7 compared the effect of 10 x 1 min interval runs at 100% MAS (HIIR) and 5 x 1 min interval runs at 100% MAS combined with a mild reduction in habitual energy intake by 0.82 MJ (195 kcal; HIIR-ER) on postprandial metabolism in 11 to 13 year old girls. Acute manipulations of low volume HIIR and ER reduced postprandial plasma [TAG] and increased resting whole-body fat oxidation, with the magnitude of effect marginally, although not meaningfully, greater following HIIR than HIIR-ER. The final experimental chapter (Chapter 8) compared directly healthy 11 to 13 year old boys and girls postprandial TAG responses to acute HIIR. Although postprandial plasma [TAG] was substantially lower in boys compared with girls, the magnitude of reduction following HIIR was similar between the sexes (11% vs. 10% respectively). Collectively, these studies demonstrate the efficacy of acute moderate- and high-intensity exercise, and to a lesser extent energy-intake restriction, to reduce postprandial plasma [TAG] and increase resting whole-body fat oxidation in boys and girls. Furthermore, the beneficial effect of exercise on postprandial metabolism appears dependent on the maintenance of the associated energy deficit. These lifestyle interventions have the potential to provide a practical, effective and engaging stimulus to promote a healthier cardiovascular risk profile in early adolescence.

Metabolomics as a field has been used to track changes and perturbations in the human body by investigating metabolite profiles indicating the change of metabolite levels over time and in response to different challenges. In this thesis work, the main focus was on applying multiplatform-metabolomics to study the human metabolome following exposure to perturbations, such as diet (in the form of a challenge meal) and exhaust emissions (air pollution exposure in a controlled setting). The cutting-edge analytical platforms used for this purpose were nuclear magnetic resonance (NMR), as well as gas chromatography (GC) and liquid chromatography (LC) coupled to mass spectrometry (MS). Each platform offered unique characterization features, allowing detection and identification of a specific range of metabolites. The use of multiplatform-metabolomics was found to enhance the metabolome coverage and to provide complementary findings that enabled a better understanding of the biochemical processes reflected by the metabolite profiles. Using non-targeted analysis, a wide range of unknown metabolites in plasma were identified during the postprandial stage after a well-defined challenge meal (in Paper I). In addition, a considerable number of metabolites were detected and identified in lung lavage fluid after biodiesel exhaust exposure compared to filtered air exposure (in Paper II). In parallel, using targeted analysis, both lung lavage and plasma fatty acid metabolites were detected and quantified in response to filtered air and biodiesel exhaust exposure (in Paper III and IV). Data processing of raw data followed by data analysis, using both univariate and multivariate methods, enabled changes occurring in metabolites levels to be screened and investigated. For the initial pilot postprandial study, the aim was to investigate the plasma metabolome response after a well-defined meal during the postprandial stage for two types of diet. It was found that independent of the background diet type, levels of metabolites returned to their baseline levels after three hours. This finding was taken into consideration for the biodiesel exhaust exposures studies, designed to limit the impact of dietary effects. Both targeted and non-targeted approaches resulted in important findings. For instance, different metabolite profiles were detected in bronchial wash (BW) compared to bronchoalveolar lavage (BAL) fluid with mainly NMR and LC-MS. Furthermore, biodiesel exhaust exposure resulted in different metabolite profiles as observed by GC-MS, especially in BAL. In addition, fatty acid metabolites in BW, BAL, and plasma were shown to be responsive to biodiesel exhaust exposure, as measured by a targeted LC-MS/MS protocol. In summary, the new analytical methods developed to investigate the responsiveness of the human plasma and lung lavage metabolome proved to be useful in an analytical perspective, and provided important biological findings. However, further studies are needed to validate these results. / Metabolomik har använts för att spåra förändringar och störningar i kroppens funktioner genom undersökning av metabolit-profiler. I detta avhandlingasarbete har huvudfokus varit på tillämpning av flera olika analytiska plattformar för metabolomikstudier av det mänskliga metabolomet efter exponering för olika kost och avgasutsläpp från biodieselbränsle. De sofistikerade analytiska plattformarna som användes för detta ändamål var kärnmagnetisk resonans (NMR), samt gaskromatografi (GC) och vätskekromatografi (LC) kopplat till masspektrometri (MS). Varje plattform erbjöd unika karakteriseringsmöjligheter med detektion och identifiering av specifika grupper av metaboliter. Användningen av multipattformmetabolomik förbättrade täckningen av metabolomet och genererade kompletterande resultat som möjliggjorde en bättre förståelse av de biokemiska processer som reflekteras av metabolitprofilerna. Med hjälp av breda analyser har ett stort antal okända metaboliter i plasma identifierats under den postprandial fasen efter en väldefinerad måltid (i Paper I). Dessutom har ett stort antal metaboliter påvisats och identifierats i lungsköljvätska efter exponering av biodieselavgaser jämfört med kontollexponering med filtrerad luft (i Paper II). Parallellt med dessa breda analyser har också riktade analyser genomförts av både lungsköljvätska och plasma. Därigenom har bioaktiva lipider detekterats och kvantifieras efter avgasexponering och resultaten har jämförts med filtrerad luft som kontrollexponering (Paper III och IV). Processning av rådata följt av dataanalys, med både univariata och multivariata metoder möjliggjorde screening och fördjupad undersökning av förändringen i metabolitnivåer. I den första pilotstudien av postprandiala nivåer var syftet att undersöka responsen i plasmametabolomet efter en väldefinierad måltid under den postprandiala fasen vid två olika typer av kost. Resultaten visade att oberoende av kosten, så återvände metabolitnivåerna till sina baslinjenivåer tre timmar efter måltiden. Detta togs i beaktande vid exponeringsstudierna för biodieselavgaser, som designades så att dietens inverkan minimerades. Både breda och riktade analyser resulterade i viktiga resultat. Exempelvis så detekterades olika metabolitprofiler i bronkiell sköljvätska (BW) jämfört med bronkoalveolär sköljvätska (BAL), speciellt med NMR och LC-MS. Dessutom resulterade avgasexponering i förändrade metabolitprofiler, observerade med GC-MS, särskilt i BAL. Dessutom uppvisade fettsyrametaboliter i BW, BAL och plasma förändrade halter efter avgasexponering, uppmätt genom en riktad LC-MS/MS-analys. Sammanfattningsvis så visade sig de nya metoderna som utvecklats för att undersöka  förändringar i metabolithalterna i plasma och lungsköljvätska fungera väl ur ett analytiskt perspektiv och resulterade i viktiga biologiska fynd. Fördjupade studier behövs dock för att validera resultaten.

La réduction des excursions glycémiques postprandiales a été proposée comme un moyen pour limiter le risque de développement du diabète de type 2. L'intérêt s'est donc porté sur les outils nutritionnels susceptibles de moduler la biodisponibilité des glucides et ainsi leur impact sur la glycémie postprandiale. Les travaux réalisés au cours de cette thèse avaient pour but d'étudier les effets de différents ingrédients modifiant la biodisponibilité du glucose, non seulement sur la glycémie postprandiale à court terme (2 heures) mais aussi sur les cinétiques du débit d'apparition et de disparition de glucose (total, exogène et endogène - isotopes stables) et les autres paramètres métaboliques de la phase postprandiale au cours de la journée. Dans la première étude (β-glucanes), nous avons montré que l'addition de fibres β-glucanes à un repas glucidique chez des sujets sains en surpoids ralentit l'absorption du glucose dans le plasma. Ceci a prolongé la réponse insulinique et par conséquent l'inhibition de la lipolyse et de la production endogène de glucose. Dans la deuxième étude (Eurostarch), nous avons montré que la diminution de la biodisponibilité du glucose au petit-déjeuner (amidon lentement digestible, index glycémique bas) diminue l'apparition du glucose exogène dans le plasma et pourrait avoir un effet second-repas chez des sujets sains en surpoids. Mais nous n'avons pas mis en évidence d'amélioration de ces effets métaboliques à plus long terme (5 semaines). Dans la troisième étude présentée (Nutriose), nous avons montré que l'addition de dextrine résistante NUTRIOSE®10 (fermentescible) au petit-déjeuner chez des sujets sains, diminue les réponses glycémiques, insuliniques postprandiales et le profil de ghréline au cours de la journée (en comparaison à une maltodextrine). En parallèle, la prolongation observée de la fermentation et l'oxydation du NUTRIOSE®10 pourraient fournir de l'énergie en phase postprandiale tardive. En conclusion, l'analyse des paramètres métaboliques au-delà de 2 heures après le repas, a permis de mettre en évidence les effets métaboliques à plus long terme de la modulation de l'apparition du glucose dans le plasma (ralentissement, prolongation, réduction) sur les cinétiques du glucose, la réponse insulinique, la lipolyse et l'oxydation des substrats

The thesis investigated the effect of exercise on endothelial function (measured as flow-mediated dilation (FMD)) and triacylglycerol concentrations following the ingestion of a high-fat breakfast and lunch in adolescent boys. The validity of measuring lipid and lipoprotein concentrations from a capillary blood sample, and the reproducibility of the postprandial FMD and triacylglycerol concentration responses to the high-fat meals, was established. The effects of prior continuous moderate-intensity exercise (60 min walking at 60% V̇O₂peak), repeated very short duration sprints (40 x 6 s maximal effort cycle sprints) and accumulated moderate-intensity exercise (6 x 10 min running at 70% V̇O₂peak) on endothelial function and triacylglycerol concentrations in adolescent boys were then established across three studies, each consisting of two, 2-day main trials (control and exercise). On day 1, participants were either inactive or completed the prescribed exercise. On day 2, FMD and triacylglycerol concentrations were measured prior to, and following, ingestion of a high-fat breakfast and lunch. In each control trial FMD was reduced (signifying endothelial dysfunction), compared to fasting, by 20-32% and 24-33% following the high-fat breakfast and lunch. Following continuous moderate-intensity exercise, repeated very-short duration sprints and accumulated moderate-intensity exercise these reductions were only 8% and 10% (main effect trial, P = 0.002; main effect time, P = 0.023; interaction effect trial x time, P = 0.088), 2% and 5% (main effect trial, P = 0.012; main effect time, P = 0.004; interaction effect trial x time, P = 0.003) and 1% and 3% (main effect trial, P = 0.020; main effect time, P < 0.001; interaction effect trial x time, P = 0.014) respectively. The continuous moderate-intensity exercise and repeated very short duration sprints also significantly reduced the total area under the triacylglycerol concentration versus time curve by 22% (Control vs. Exercise; 12.68 (sem 1.37) vs. 9.84 (sem 0.75) mmol L-1 6.5h, P = 0.018) and 13% (Exercise vs. Control: 8.65 (sem 0.97) vs. 9.92 (sem 1.16) mmol L-1 6.5h, P = 0.023). The accumulated moderate-intensity exercise also reduced the total area under the triacylglycerol concentration versus time curve by 11%, but this reduction was not significant (Control vs. Exercise: 10.71 (sem 0.94) vs. 9.56 (sem 0.67) mmol L-1 6.5h, respectively, P = 0.183). The experimental evidence from these studies emphasise that exercise might offer an acceptable, non-pharmacological means of influencing CHD risk when individuals are young. The results of these studies can help shape future physical activity guidelines.

La lipémie postprandiale se caractérise par une augmentation des lipoprotéines riches en triglycérides après un repas, et joue un rôle important dans la biodisponibilité des lipides alimentaires pour les tissus périphériques. En effet, une lipémie postprandiale élevée est souvent associée à l'obésité et à une dyslipidémie, deux composantes du syndrome métabolique qui peuvent engendrer des complications médicales, incluant diabète et maladies cardiovasculaires. La lactoferrine (Lf) inhibe l'épuration hépatique des chylomicrons, conduisant à une élévation de la lipémie postprandiale par des mécanismes moléculaires non élucidés. Il est aussi établi que le Lipolysis Stimulated Receptor (LSR) contribuait à l'épuration des lipoprotéines riches en triglycérides pendant la phase postprandiale. L'objectif était de déterminer s'il existait une interaction entre la Lf et le LSR. Les études de cultures cellulaires ont montré que si la Lf n'affectait pas le taux d'expression du LSR dans des cellules Hepa 1-6 de souris, elle co-localisait avec le LSR en présence d'oléate, un composé requis pour l'activation du récepteur. Des expériences de ligand-blotting ont également montré que la Lf se fixait sur le LSR purifié et inhibait la fixation de lipoprotéines riches en triglycérides. Les domaines N et C-terminaux isolés de cette protéine, ainsi qu'un mélange de peptides obtenu après double hydrolyse de la Lf par la trypsine et la chymotrypsine, conservent cette propriété. Nous proposons que l'élévation de la lipémie postprandiale observée in vivo suite à un traitement par la Lf soit médiée par son interaction avec le LSR, inhibant ainsi l'épuration des chylomicrons et de leurs remnants / Postprandial lipemia is characterized by an increase in plasma triglyceride-rich lipoproteins after the ingestion of meal, and is important towards determining the bioavailability of dietary lipids amongst the peripheral tissues. Indeed, elevated postprandial lipemia is often observed with obesity and dyslipidemia, two disorders that can lead to health complications including diabetes and cardiovascular diseases. Lactoferrin (Lf), has been shown to inhibit hepatic chylomicron remnant removal, resulting in increased postprandial lipemia, for which the molecular mechanisms remain unclear. The lipolysis stimulated lipoprotein receptor (LSR) has been shown to contribute to the removal of triglycerides-rich lipoproteins during the postprandial phase. The aim was to determine if there was interaction between Lf and LSR. Both Lf and LSR were purified with purities upper to 95% and characterized. Cell culture studies demonstrated that while Lf does not have any significant effect on LSR protein levels in mouse Hepa1-6 cells, it co-localizes with LSR in cells, but only in the presence of oleate, which is needed to obtain LSR in its active form. Ligand blotting using purified LSR revealed that Lf binds directly to the receptor in the presence of oleate and prevents the binding of triglycerides-rich lipoproteins. Both C- and N-lobes of Lf, and a mixture of peptides derived from its tryptic and chymotryptic double hydrolysis retained the ability to bind LSR. We propose that the elevated postprandial lipemia observed upon Lf treatment in vivo is mediated by its direct interaction with LSR, thus preventing clearance of chylomicrons and their remnants through the LSR pathway

Made available in DSpace on 2014-06-11T19:28:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-04Bitstream added on 2014-06-13T18:57:28Z : No. of bitstreams: 1 martins_ms_me_jabo.pdf: 1334577 bytes, checksum: 558ffb190a2980722ebcf5da43d4c243 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O objetivo do presente estudo foi determinar por meio dos métodos de substituição, os coeficientes de digestibilidade aparente (CDA) das leveduras de cerveja e de cana-de-açúcar autolisada e íntegra, e de inclusão de teores crescentes das leveduras de cana-de-açúcar em dietas extrusadas para cães adultos. Dois ensaios foram conduzidos; no primeiro foi utilizado o método de substituição e 4 dietas experimentais, uma dieta referência isenta de levedura e outras três compostas pela substituição de 15% da dieta basal por leveduras de cerveja e de cana-de-açúcar autolisada e íntegra, respectivamente. Para o segundo ensaio foram utilizados 35 cães adultos distribuídos em 5 tratamentos e 7 repetições por dieta, estas sendo: 0 (basal), 7,5 e 15% de levedura de cana-de-açúcar autolisada e 7,5 e 15% de íntegra. No primeiro ensaio, os CDA da PB são 96,47, 62,98 e 74,70% e da EB 84,01, 68,43 e 75,95%, respectivos as leveduras; havendo diferença entre as leveduras avaliadas apenas para o CDA da PB (p<0,05). No segundo ensaio, os tratamentos não se mostraram diferentes quanto a digestibilidade para os nutrientes MS, MO, EEA, FDN e EB (p>0,05). As energias das dietas acima são respectivamente (Kcal/Kg MS): ED (4107,74; 3995,23, 3922,53; 4066,7; 3921,15) e EM (3714,96; 3749,46; 3667,53; 3876,23; 3673,16) e os CDA (%): MS (81,95; 82,13; 79,14; 80,79; 80,59), MO (86,56; 85,88; 83,68; 85,09; 85,07), PB (84,68; 85,20; 81,90; 83,31; 82,89), EEA (83,68; 83,58; 81,28; 83,82; 82,69), FB (44,99; 33,10; 30,14; 37,33; 22,37), FDN (47,40; 54,20; 45,36; 46,70, 50,99) e EB (86,03; 85,09; 82,54; 84,81; 84,13). A utilização da levedura de cana-de-açúcar não influenciou o CDA das dietas para MS, MO, PB, EEA, FDN, EB e EM das dietas (p<0,05), porém prejudicou linearmente, conforme aumento na inclusão das leveduras de cana-de-açúcar, o CDA da FB e ED (p>0,05). Conforme aumento na... / The present study aimed to determine, for dogs, the digestibility of the brewer’s yeast and sugar cane yeast, autolyzed and integral, and the diets’ nutrients that used the sugar cane yeast in increasing inclusions. Two metabolism assays were performed, the first one had used the substitution method to define the digestibility of the ingredients tests, being made one without yeast (control) and others 3 tests diets (15% brewer’s yeast, sugar cane autolyzed and integral + 85% control diet). In the second assay, it was used 35 adult dogs distributed in 5 treatments with 7 replications for each diet. These were: 0 (control), 7,5 and 15% sugar cane yeast autolyzed and 7.5 and 15% of integral yeast. In the first assay, the coefficients of apparent digestibility (CAD) of the CP were 96.47, 62.98 and 74.70%, and CE 84.01, 68.43 and 75.95%, respectively from yeasts; just the CP was different between the yeast evaluated (p<0,05). In the second assay, the treatments weren’t difference for the dry matter (DM), organic matter (OM), acid ether extract (AEE), neutral detergent fiber (NDF) and crude energy (CE) between the ingredients. The energies from diets were respectively (Kcal/Kg CM): digestible energy (DE) (4,107.74; 3,995.23; 3,922.53; 4,066.7; 3,921.15) and metabolizable energy (ME) (3,714.96; 3,749.46; 3,667.53; 3,876.23; 3,673.16) and the CAD (%): DM (81.95; 82.13; 79.14; 80.79; 80.59), OM (86.56; 85.88; 83.68; 85.09; 85.07), CP (84.68; 85.20; 81.90; 83.31; 82.89), AEE (83.68; 83.58; 81.28; 83.82; 82.69), crude fiber (CF) (44.99; 33.10; 30.14; 37.33; 22.37), NDF (47.40; 54.20; 45.36; 46.70, 50.99) and CE (86.03; 85.09; 82.54; 84.81; 84.13). The sugar cane yeast did not affect the diets’ CAD of DM, OM, AEE, NDF and ME of the diets (p<0.05); but, the CDA had a linear reduction in CP, CF, CE and DE (p>0.05) with the increasing inclusions. Therefore, the brewer’s yeast presented ... (Complete abstract click electronic access below)

Made available in DSpace on 2014-12-17T14:03:32Z (GMT). No. of bitstreams: 1 LahyanaRFC.pdf: 2685463 bytes, checksum: 7db6843f1628ffaeb8a563aad621ade6 (MD5) Previous issue date: 2010-02-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Vitamin A is important in many essential body processes and its deficiency results in serious consequences for human health. Breast milk is the only source of this vitamin for children that are exclusively breastfed. Analysis of vitamin A in mother s milk is important because its concentration is related to maternal vitamin A status and to its ingestion by the mother during pregnancy. The aim of the present study was to assess the effect of maternal supplementation with retynil palmitate on the concentration of colostrum retinol under fasting and postprandial conditions. A total of 149 nursing mothers were recruited at the Janu?rio Cicco Maternity School (Natal, Brazil) and allocated to two groups: Comparison (n = 69) and Test (n = 80). Blood and colostrum (in fasting and postprandial conditions) samples were collected up to 24hs after delivery. Serum retinol and colostrum levels were analyzed by high-performance liquid chromatography. The serum retinol level of 41.6 ? 12.7?g/dL (mean ? standard deviation) indicates adequate biochemical nutritional status. Colostrum retinol level was not influenced by serum retinol levels under any of the conditions established. In the colostrum, the retinol concentration in the unsupplemented test group was 67.3 ? 37.7 ?g/dL under fasting and 80.3 ? 35.1 ?g/dL under postprandial conditions (p<0.05), showing an increase of 19.3%. In the supplemented test group the values were 102.6 ? 57.3 ?g/dL and 133.4 ? 78.3 ?g/dL under fasting and postprandial, respectively (p<0.05), representing an increase of 30%. Considering that under fasting conditions most of the vitamin A transported to the milk originates in the retinol binding protein (RBP), the postprandial increase in colostrum retinol suggests a different transport mechanism of retinol to maternal milk from that performed by RBP. This situation becomes more evident under supplementation conditions. / Vitamina A ? importante em muitos processos essenciais no corpo e sua defici?ncia resulta em severas conseq??ncias para a sa?de dos seres humanos. O leite humano ? a ?nica fonte dessa vitamina para crian?as que s?o amamentadas de forma exclusiva. A an?lise da vitamina A no leite materno ? importante, porque a sua concentra??o neste fluido est? relacionada com o estado de vitamina A materno e com a ingest?o desta vitamina pela m?e durante a lacta??o. Assim, o objetivo do presente trabalho foi avaliar o efeito da suplementa??o materna com palmitato de retinila sobre a concentra??o de retinol no colostro em condi??es de jejum e p?s-prandial. Para isso, foram recrutadas 149 nutrizes saud?veis da Maternidade Escola Janu?rio Cicco (Natal- RN), sendo os grupos Compara??o 69 e Teste 80. Amostras de sangue, colostro em jejum e colostro p?s-prandial foram coletadas at? 24hs ap?s suplementa??o. As concentra??es de retinol no soro e colostro foram analisadas por cromatografia l?quida de alta efici?ncia. A concentra??o s?rica de retinol de 41,6 ? 12,7?g/dL (m?dia ? desvio-padr?o) indica estado nutricional bioqu?mico adequado. A concentra??o de retinol no colostro n?o foi influenciada pelos n?veis s?ricos de retinol, em nenhuma das condi??es estabelecidas. No colostro, a concentra??o do retinol no grupo teste sem suplementa??o foi de 67,3 ? 37,7 ?g/dL no jejum e de 80,3 ? 35,1 ?g/dL no p?sprandial (p<0,05), evidenciando um aumento de 19,3%. No grupo teste suplementado os valores foram de 102,6 ? 57,3 ?g/dL e 133,4 ? 78,3 ?g/dL no jejum e p?s-prandial, respectivamente (p<0,05), representando um aumento de 30%. Considerando que no jejum a maior parte da vitamina A transportada ao leite tem sua origem atrav?s da prote?na transportadora de retinol (RBP), o aumento no retinol do colostro p?s-prandial sugere um mecanismo de transporte do retinol para o leite materno distinto daquele realizado pela RBP. Tal situa??o fica mais evidente em condi??es de suplementa??o.