Foram utilizadas 8 vacas Holandesas em lactação, distribuídas em um quadrado latino (4x4), replicado, conduzidos durante o verão, por um período de 72 dias. O objetivo desse trabalho foi estudar quatro níveis de dietas catiônicas, sobre a IMS, produção, composição e propriedades físico-químicas do leite, pH urinário, temperatura corporal e parâmetros ácido-base do sangue, em vacas após o pico de lactação. Para a manipulação do BCAD, foram adicionadas diferentes concentrações de bicarbonato de sódio nas dietas, obtendo-se os seguintes tratamentos: +150, +250, +400 e +500mEq/kg MS. A temperatura corporal das vacas não foi afetada pelo balanço cátion-aniônico da dieta. O bicarbonato, o pH, o CO2 total e a pCO2 do sangue aumentaram linearmente com o aumento do BCAD. A concentração de cálcio no sangue apresentou resposta quadrática, com maior valor para o menor BCAD. As concentrações de sódio e potássio do sangue não foram modificadas significativamente pelo BCAD e a concentração de cloro diminuiu linearmente com o aumento do BCAD. O aumento do BCAD resultou em aumento da ingestão de matéria seca e produção de leite. Não houve diferença significativa para as variáveis: porcentagem de gordura, densidade e índice crioscópico, do leite. O pH do leite aumentou linearmente e a acidez apresentou resposta cúbica, com o aumento do BCAD. Conclui-se que a manipulação do BCAD afeta o equilíbrio ácido-base das vacas, mesmo dentro de variação positiva. Devido ao aumento da IMS e da produção de leite, verificou-se efeito benéfico do uso de dietas catiônicas, para vacas após o pico de lactação. / Eight lactating Holsteins cows were distributed in 4 x 4 replicated Latin square, during the summer, for a period of 72 days. The objective of this research was to study the effect of four cationic diets levels, on the dry matter intake, milk production, composition, and physico-chemical parameters, urinary pH, body temperature and blood acid-base parameters, in cows, after the lactation peak. For DCAB manipulation were added different concentrations of sodium bicarbonate in the diets and the following treatments were obtainned: +150, +250, +400 e +500mEq/kg DM. The cows body temperature was not affected by dietary cation-anion balance. Blood bicarbonate, pH, total CO2 and pCO2 increased linearly with the increase of dietary CAB. Calcium concentration in the blood decreased quadratically with dietary CAB increased. Sodium and potassium concentration in the blood were not modified significantly with the DCAB and concentration of chloride decreased linearly with increase of DCAB. Increasing BCAD resulted in higher DM intake and milk yield. The diets did not affect milk fat percentage, density and crioscopic index. Milk pH increased linearly and acidity decreased cubically with the increase of dietary CAB. It was concluded that DCAB manipulation affected the acid-base status of cows, even inside of positive variation. Due to the increase of DM intake and milk yield, it was verified a beneficial effect of the cationic diets for cows after the lactation peak.

Cento e sessenta ovelhas, no terço final da gestação, foram distribuídas em delineamento de blocos completos casualizados, para avaliar os efeitos da diminuição da concentração de CNF na dieta pré e pós-parto, sobre a lactação e o desempenho das crias após o nascimento. As dietas experimentais foram compostas por 50% de volumoso (feno de \"coastcross\") e 50% de concentrado, sendo o milho o principal ingrediente utilizado na dieta com mais CNF e a casca de soja o principal ingrediente da dieta com reduzido CNF, correspondendo aos tratamentos M e CS, respectivamente. Foram avaliados o CMS e as concentrações de glicose, insulina e ácidos graxos não esterificados (AGNE), 3h após a oferta de alimento nos dias 21 e 7 antes do parto e imediatamente após a parição. No dia do parto foi avaliado o peso e o escore da condição corporal (ECC) das ovelhas. Da segunda à 12ª semana de lactação, 38 ovelhas e suas respectivas crias foram utilizadas para avaliar a lactação. Após a parição as ovelhas permaneceram nos tratamentos experimentais (M e CS) pré-parto e foram blocadas de acordo com a data do parto, o sexo e o número de crias. Uma vez por semana as ovelhas foram separadas de suas crias e ordenhadas mecanicamente. Três horas após a 1° ordenha, as ovelhas foram novamente ordenhadas e a produção de leite registrada. Também foram avaliados o CMS diário, o ECC, nas semanas 3, 6, 9, e 12 pós-parto, e as concentrações séricas de glicose, insulina e AGNE, 0 e 3h após o fornecimento das dietas, na 2ª, 4ª, 6ª, 8ª, 10ª e 12ª semanas de lactação. O efeito do tratamento materno sobre o desenvolvimento das crias foi avaliado através do peso ao nascimento, GMD e CMS durante o aleitamento. No confinamento, além do GMD e o CMS, foram determinados a eficiência alimentar e as características das carcaças ao abate. No final da gestação a dieta CS promoveu aumento do CMS e maior peso das fêmeas ao parto, assim como maior peso das crias ao nascimento. Entretanto, não houve alteração no ECC e nas concentrações de glicose, insulina e AGNE. Durante a lactação, não houve efeito das dietas na produção e composição do leite. Houve aumento na concentração de AGNE, às 3 h após alimentação, para o grupo CS sem diferença para as demais variáveis sanguíneas. Não houve diferença no desempenho dos cordeiros durante o aleitamento ou no confinamento. A diminuição de CNF da dieta de ovelhas pré-parto aumenta o CMS, resultando em maior peso ao parto, assim como maior peso das crias ao nascimento. Entretanto, no período pós-parto não altera o desempenho das crias e das ovelhas na lactação, mas aumenta a concentração de AGNE 3 h após a alimentação. / One hundred and sixty ewes, in the last third of gestation, were allotted in a randomized complete block design to determine the effects of lowering the concentration of NFC in the pre and postpartum diets on lactation performance and offspring growth. The experimental diets were composed of 50% roughage (coastcross hay) and 50% concentrate, with corn being the main ingredient used in the diet with high NFC and soybean hulls as the main ingredient of the diet with reduced NFC, corresponding to treatments C and SH, respectively. Dry matter intake (DMI) and the concentrations of glucose, insulin and non-esterified fatty acids (NEFA), 3h after feeding, in the days 21 and 7 prior and immediately after lambing. At lambing, ewes and lambs were weighed and ewe\'s body condition score (BCS) was recorded. From the second to the 12th week of lactation, 38 ewes and their offspring were used to evaluate lactation performance and lamb growth. After lambing, the ewes remained in the experimental pre-natal treatments (C and SH) and were blocked according to date of birth, sex and number of offspring. Once a week the ewes were separated from their lambs and mechanically milked. Three hours after the 1st milking, the ewes were again milked and the production was recorded. In addition it was determined the daily DMI, the BCS, in weeks 3, 6, 9, and 12 postpartum, and blood concentrations of glucose, insulin and NEFA, 0 and 3 hours after feeding, in the 2nd , 4th , 6th , 8th , 10th and 12th weeks of lactation. The effects of maternal diet on the growth of offspring were assessed by birth weight, ADG and DMI. During the feedlot, in addition to ADG and DMI, feed efficiency and carcass characteristics at slaughter were determined. In late gestation reducing NFC increased DMI and weight of ewes at parturition, as well as lambs birth weight. However, there was no change in BCS and in the concentrations of glucose, insulin and NEFA. During lactation, there was no difference in the ewe\'s milk production and lamb\'s growth. An increase in the concentration of NEFA, 3 hours after feeding, was observed for the SH group, with no difference for the other blood variables. Reducing pre-partum dietary NFC increases DMI, ewes lambing weight and lambs birth weight. However, in the postpartum period there was no change on ewe\'s lactation performance and lamb\'s growth, only an increase in the concentration of NEFA, 3h after feeding.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Alterações nutricionais, hormonais e ambientais nos períodos críticos do desenvolvimento como a gestação e/ou lactação podem influenciar a estrutura e a fisiologia de órgãos e tecidos, predispondo ao aparecimento de doenças na vida adulta. Esse fenômeno é conhecido como programação metabólica. O fumo materno na gestação/lactação tem sido associado ao sobrepeso/obesidade na infância e na vida adulta em ambos os sexos. Porém, estudos evidenciam diferenças entre os gêneros em resposta a exposição à nicotina. Já foi demonstrado que muitas mulheres param de fumar na gestação, mas a maioria destas volta a fumar na lactação. Anteriormente, mostramos que machos adultos cujas mães foram expostas à nicotina na lactação, desenvolveram obesidade central, hiperleptinemia e hipotireoidismo. Como a nicotina afeta a função adrenal e como catecolaminas e glicocorticóides têm efeitos bem conhecidos sobre o tecido adiposo, avaliamos a função da medula adrenal e o conteúdo de leptina no tecido adiposo e músculo de machos e fêmeas cujas mães foram expostas à nicotina na lactação. Dois dias pós-parto, implantamos minibombas osmóticas nas ratas lactantes dividas em: NIC infusão de nicotina (6mg/Kg/dia s.c.) por 14 dias, e C infusão de salina pelo mesmo período. Estas lactantes foram divididas de acordo com o sexo das proles. O sacrifício das proles de ambos os sexos ocorreu aos 15 (fim da exposição à nicotina) e 180 dias de vida. Aos 15 dias, os machos da prole NIC apresentaram aumento de MGV absoluta e relativa ao peso corporal (+72% e +73% respectivamente), hiperleptinemia (+35%), hipercorticosteronemia (+67%), maior peso adrenal (+39%), conteúdo de catecolaminas totais (absoluto: +69% e relativo: +41%), embora diminuição da enzima TH (-33%). Quando adultos, os machos programados exibiram maior massa corporal (+10%), MGV absoluta (+47%) e relativa (+33%), além de hiperleptinemia (+41%) e maior conteúdo de leptina no TAV (+23%). Esses animais também apresentaram hipercorticosteronemia (+77%), maior conteúdo de catecolaminas totais absoluto e relativo (+79% e +89% respectivamente) e de TH (+38%) embora tenham menor secreção de catecolaminas in vitro estimulada por cafeína (-19%) e maior expressão do ADRB3 no TAV (+59%). Em relação as fêmeas da prole NIC aos 15 dias de vida, estas apresentaram menor massa corporal (-6%) e hiperleptinemia (+41%) embora sem alteração da MGV. Aos 180 dias, as fêmeas da prole NIC apresentaram menor conteúdo de leptina no TAS (-46%) e maior conteúdo de leptina no músculo solear (+22%) e diminuição da expressão do ADRB3 no TAV (-39%). Concluímos que a nicotina materna afeta ambos, medula adrenal e tecido adiposo de forma gênero dependente, tanto em curto prazo (quando a nicotina está presente no leite materno), quanto em longo prazo (repercussões na vida adulta). De forma geral, as fêmeas da prole NIC apresentam alterações mais discretas do que os machos em ambos os períodos estudados. / Nutritional, hormonal and environmental changes during critical periods of life (pregnancy and/or lactation) are associated with future changes in the structure and physiology of body tissues and systems, influencing some diseases in adulthood. This phenomenon is known as metabolic programming. Maternal smoking during pregnancy/lactation has been associated with overweight/obesity in childhood and adulthood in both genders. However, studies have shown gender differences in response to nicotine exposure. Although many women quit smoking during pregnancy, data reveal that most women who stop smoking during gestation relapse during lactation. Previously, we showed that adult male rats whose mothers received nicotine during lactation developed overweight, hyperleptinemia and hypothyroidism. Because nicotine affects the adrenal function and, as glucocorticoids and catecholamines have well known effects on adipose tissue, we evaluated adrenal medulla function and leptin content in adipose tissue and muscle of males and females whose dams were nicotine-treated during lactation. On postnatal (PN) day 2, dams were subcutaneously implanted with osmotic minipumps releasing nicotine (6mg/Kg/day) for 14 days of lactation (NIC) or saline. Male and female offspring were killed at 15 and 180 days-old. In PN15, males of NIC group presented higher absolute (+72%) and relative (+73%) VFM, hyperleptinemia (+35%), hypercorticosteronemia (+67%), higher adrenal weight (+39%) and adrenal catecholamine content (absolute: +69% and relative: +41%) although lower TH content (-33%). In PN180, these males displayed higher body mass (+10%), absolute (+47%) and relative (+33%) VFM, hyperleptinemia (+41%), higher leptin content in VAT (+23%), hypercorticosteronemia (+77%), higher adrenal catecholamine content (absolute:+79% and relative:+89%), higher TH expression (+38%), lower in vitro catecholamine release (-19%) and higher ADRB3 content in VAT (+59%). Females of NIC group at PN15 presented lower body mass (-6%) and hyperleptinemia (+41%) but no change in VFM. In PN180, these females showed lower leptin content in SAT (-46%), higher leptin content in muscle (+22%) and lower ADRB3 content in VAT (-39%). Thus, we evidenced a sex dimorphism in the model of programming by maternal nicotine exposure during lactation. The medullary adrenal function and corticosteronemia in adult rat were programmed only in male offspring while the female offspring displayed relevant alterations in leptin content.

<p>Period rane laktacije odlikuje se nagatvnim energetskim bilansom i stanjem metaboličkog stresa. Ovakvo stanje nastaje kao posledica smanjenog unosa hrane, porođaja i započinjanja laktacije. Usled negativnog energetskog bilansa organizam povećano tro&scaron;i sopstvene reserve I ulazi u fazu katabolizma. Cilj ove disertacije je da se ispita metabolička, hematolo&scaron;ka, celularna i proizvodna adaptacija krava u funkciji delovanja anaboličkih i kataboličkih indikatora stresa. Katabolički indikatori stresa su: neesterifikovane masne kiseline (čija koncentracija raste kao posledica povećane lipidne mobilizacije) i kortizol (čija vrednost raste usled stresa tokom porođaja). Anabolički indikatori su: insulin (anabolički hormone u organizmu sisara) i IGF-I (indikator anaboličkog delovanja STH). Krave su klasifikovane na osnovu pojedinačnog i kombinovanog delovanja anaboličkih i kataboličkih indikatora stresa. Upotreba četiri odabrana indikatora metaboličkog stresa (insulin, IGF-I, NEFA i kortizol) u prvoj nedelji posle teljenja može pomoći u analizi metaboličkog stresa i produktivnosti krava, &scaron;to se zaključuje na osnovu delovanja indikatora<br />Created by Simpo PDF Creator Pro (unregistered version) http://www.simpopdf.com<br />c<br />stresa na metabolički profil, krvnu sliku, imunolo&scaron;ke i celularne parametre, telesnu kondiciju, proizvodnju mleka i reproduktivnu efikasnost krava. Vrednosti anaboličkih i kataboličkih indikatora se mogu koristiti samostalno ili u kombinaciji, a najbolju mogućnost procene daje upotreba NEFA bilo da se radi o pojedinačnoj ili kombinovanoj upotrebi indikatora.Određivanjem koncentracije navedena četiri indikatora metaboličkog stresa u prvoj nedelji posle teljenja možemo predvideti karakter metabolizma, dubinu metaboličkog stresa i proizvodnju krava u laktaciji koja sledi.</p> / <p>Early lactation period is characterized by negative energy balance and metabolic stress condition. This situation arises as a consequence of reduced food intake, birth and initiation of lactation. Due to negative energy balance increased body using own reserves and is entering to a phase of catabolism. The goal of this dissertation is to examine the metabolic, hematologic, and cellular adaptation of cows in production function and anabolic activity of catabolic stress indicators. Catabolic stress indicators are nonesterified fatty acids - NEFA (whose concentration increases as a result of increased lipid mobilization) and cortisol (the value of which increases due to stress during labor). Anabolic indicators were: insulin (anabolic hormones in mammals) and IGF-I (an indicator of anabolic activity STH). Cows were classified on the basis of individual and combined effects of anabolic and catabolic stress indicators. Using the four selected indicators of metabolic stress (insulin, IGF-I, NEFA and cortisol) in the first week after calving can help in the analysis of metabolic stress and productivity of cows, which<br />Created by Simpo PDF Creator Pro (unregistered version) http://www.simpopdf.com<br />f<br />concludes on the basis of indicators of stress effects on metabolic profile, blood count, and cellular immune parameters, body condition, milk production and reproductive efficiency of cows. Anabolic and catabolic values of indicators may be used singly or in combination, and provides the best opportunity to assess the use of NEFA either a single or combined use of indicators. It is possible to use concentrations of the four indicators of metabolic stress in the first week after calving predict the nature of metabolism, metabolic stress and depth of production in cows in the next lactation.</p>

Dois experimentos foram conduzidos com o objetivo de estudar a inclusão de uréia em nível elevado na dieta (2% da MS), na forma tradicional ou extrusada com milho (Amiréia 150S), em substituição parcial ao farelo de soja em dietas para vacas leiteiras. No experimento 1 foram utilizadas 38 vacas Holandesas em final da lactação, com produção média de 20 kg de leite/d, em um delineamento em blocos ao acaso. O período experimental teve a duração de 60 dias. As dietas eram compostas por silagem de capim elefante aditivada com polpa cítrica peletizada, raspa de mandioca, polpa cítrica peletizada, suplemento mineral e vitamínico e os respectivos suplementos protéicos: a) farelo de soja; b) farelo de soja + amiréia; c) farelo de soja + uréia. Os parâmetros avaliados foram consumo de matéria seca, produção e composição do leite, extração de aminoácidos pela glândula mamária e concentração de glicose e nitrogênio uréico no plasma sangüíneo. No experimento 2 foram utilizadas 5 vacas Holandesas canuladas no rúmen e duodeno, no período seco. Os tratamentos foram os mesmos utilizados no experimento 1. Os parâmetros avaliados foram consumo de matéria seca e nutrientes, digestibilidade de nutrientes no trato digestivo total, produção de ácidos graxos voláteis, pH e concentração de nitrogênio amoniacal no rúmen e parâmetros sangüíneos (glicose e nitrogênio uréico no plasma). No experimento 1, a substituição parcial do farelo de soja por fontes de nitrogênio não protéico, assim como o processamento da uréia na forma extrusada, não afetaram a produção de leite, leite corrigido para gordura, teor e produção de proteína e lactose do leite, produção de sólidos totais, concentração de nitrogênio ureico e glicose no plasma (P>0,05). O teor e produção de gordura, teor de sólidos totais e eficiência de extração de aminoácidos pela glândula mamária foram maiores para o tratamento com uréia na forma tradicional (P<0,05). No experimento 2 não foram observadas diferenças para consumo e digestibilidade aparente no trato total da matéria seca e nutrientes, concentração total de ácidos graxos voláteis no fluido ruminal, porcentagem molar dos ácidos acético, propiônico e butírico em relação ao total de ácidos graxos voláteis, relação acético:propiônico, concentração e nitrogênio ureico e glicose no plasma, (P>0,05). O pH do fluido ruminal se manteve mais elevado nas primeiras horas após a alimentação no tratamento uréia em relação aos demais (P<0,05). Ambas as fontes de NNP, apresentaram valores mais elevados de nitrogênio amoniacal no fluido ruminal (P<0,05). A substituição parcial do farelo de soja por uréia no teor de 2% da matéria seca da dieta é uma alternativa viável em dietas para vacas leiteiras em final de lactação e no período seco. O processamento da uréia na tentativa de reduzir a velocidade de liberação de amônia no rúmen, não apresentou vantagens em relação à uréia na forma convencional. / Two trials were conducted to study the partial replacement of soybean meal by high level (2% of DM) of urea in diets for late lactation dairy cows. Conventional urea also was compared to urea extruded with a starch source (Starea - 150S). In trial 1, 38 late lactation Holstein cows producing around 20 kg of milk/d, were used in a randomized block design. The experimental period lasted 60 days. Diets were composed by elephant grass silage with dried citrus pulp, tapioca meal, dried citrus pulp, tallow, mineral and vitamin mix and the protein supplements. The treatments were: a) soybean meal (FS); b) soybean meal + starea (A150S); c) soybean meal + urea (U). The partial replacement of soybean meal by high levels of NPN sources or the urea processing, did not affect milk and 3,5% FCM yields, protein content and yield, total solids yield, and plasma urea N and glucose. Feeding 2% of urea (U) increased milk fat and total solids content and the efficiency of amino-acids extraction by the mammary gland. In trial 2, 5 dry Holstein cows, fitted with ruminal canulas, were fed the same treatment diets used in trial 1 (corn silage was used instead of grass silage). Dry matter intake, total tract nutrient digestibility’s, total rumen VFA molar concentration and acetic, propionic and butyric acid molar proportion, plasma urea-N and plasma glucose were not affected by treatments (P>0,05). Rumen pH was higher for U diet, 2 to 4 hours post-feeding, and rumen ammonia N was higher for U and A150S diets (P<0,05). The partial replacement of soybean meal by high levels of urea, is an alternative to reduce costs of diets for late lactating cows milking around 20 kg/d. Extrusion of urea with a starch source, in attempt to slow ammonia release in the rumen (A150S), did not show any advantage compared to conventional urea.

Many factors influence the nutrient composition of breast milk (BRM) particularly within the fatty acids composition. In this study BRM between 2-14 weeks of lactation was collected from 44 Caucasian women (24 normal weight (NW, BMI 18.5-24.9kg/m2) and 20 overweight (OW, BMI >25.0kg/m2). BRM was subjected to proximate analysis and participants completed food frequency questionnaires (FFQ) to estimate fruit, vegetable, and fat intake. BMI differed between NW and OW groups, 22.03 vs 33.86kg/m2 (p0.10) were identified for total calories (5,581.8 vs 5562.9cal/g), %fat (39.6 vs 43.9), or %protein (9.8 vs 8.9) for BRM in NW versus OW women as determined by proximal analysis. Gas chromatography of fatty acid methyl esters demonstrated NW BRM contained higher levels of omega-3, mono-unsaturated, and less palmitic acid fatty acids (p>0.10). The increased palmitic acid level seen in OW BRM may support increased de novo synthesis of fatty acids.

Breastfeeding is the best infant feeding method, and breastmilk has many immunological and anti-inflammatory properties that protect babies against illnesses and diseases. It protects the health of the mother and saves society substantial economic costs, as demonstrated in many studies. Studies show that if 90% of U.S mothers breastfed for 6 months, up to $13 billion in healthcare costs could be saved. Despite the health and economic benefits of breastfeeding, most women stop breastfeeding before 6 months postpartum, which falls short of the recommendations of the World Health Organization, U.S. Surgeon General, and American Academy of Pediatrics. This study explored the effects of hand expression with lactation support on first-time mothers' self-efficacy for breastfeeding and breastfeeding duration among vaginal and Cesarean delivery mothers at a healthcare center in Oregon. The pretest posttest quasi-experimental design was used on 32 women with 4 repeated-measures ANOVA, and the women were followed up for 6 weeks postpartum. The women in the intervention group received the hand-expression intervention after the first breastfeeding until their white milk had been established. Results showed a large effect of the hand-expression intervention with lactation support on the dependent variable of self-efficacy, with an effect size of 0.888, and the dependent variable of breastfeeding duration, with an effect size of 0.801. Further, self-efficacy and breastfeeding duration increased over time. The results may inform policy development to increase women's self-efficacy and breastfeeding duration, which could help babies, mothers, and society to derive maximum benefits from breastfeeding.

Third-cutting alfalfa hay harvested at bud stage in each of 2 yrs, treated with a live bacterial incoulant, packed in polyethylene-bonded bags and allowed to ensile. In both years, treated haylage had a lower pH, and a period effect was found for pH and mold count, regardless of treatment. In year 1, there was a period effect found for acid detergent fiber. In year 2, mean lactic-acid-producing bacteria numbers (log 10) were significantly higher for treated haylage (9.69 and 10.36) for control and treated haylage, respectively). Regardless of treatment, lactic-acid-producing bacteria numbers and water soluble carbohydrates significantly declined through time. For both years, treated haylage was fed to early-lactating dairy cows at 60% of the ration dry matter. In year 1, lactating cows were fed treated haylage for a 10-wk period, and no differences were observed in milk production performance or dry matter intake over cows fed untreated haylage. In year 2, cows were fed for a 6-wk period, and no differences were detected between treatments for milk production, milk composition, or dry matter intake.

L’obésité, problème majeur de santé publique, est en augmentation constante. Elle est responsable d’une altération de la sécrétion des adipokines, telles que l’apeline. L’apeline est impliquée dans diverses fonctions de l’organisme et notamment dans la régulation du métabolisme énergétique. Au cours de la grossesse, ce système semble avoir un rôle crucial dans le développement foeto-placentaire. Le système apelinergique chez la femme enceinte obèse n’a encore jamais été étudié. L’objectif de cette thèse était de vérifier si le système apelinergique est modifié en cas d’obésité chez la femme enceinte, tout d’abord par une approche expérimentale sur un modèle de souris obèse et insulino-résistante, puis par une approche translationnelle vers l’humain (étude OB-APE). Matériel et méthode : Modèle murin : 40 souris femelles ont été réparties en 2 groupes : Témoin (T, n=20) et High Fat (HF, n=20). Après 3 mois de régime, les souris étaient mises en reproduction. Des prélèvements étaient réalisés à E6.5, E12.5 et E18.5. Lors du sacrifice à E18.5, la glycémie à jeun, l’insulinémie, l’apelinémie maternelle et foetale étaient dosées, les souriceaux et les placentas étaient pesés. La moitié de chaque placenta était mis dans du RNA later et l’autre moitié était mis dans de l’azote liquide. Les prélèvements étaient conservés à -80°C. Etude chez l’humain (étude OB-APE) : Etude prospective et comparative menée au sein de la maternité Jeanne de Flandre (Lille, France) entre mai 2016 et juillet 2017. Les patientes inclues étaient réparties en 3 groupes: N (normal, n= 30), O (obèses, n = 30) et ODG (obèse avec diabète gestationnel, n = 30). Trois prélèvements plasmatiques maternels d’apeline étaient réalisés : entre 35 et 40 SA), à l’accouchement et au 2ème jour du post-partum, ainsi qu’un prélèvement néonatal au cordon ombilical. Des fragments placentaires étaient prélevés à l’accouchement et du colostrum était récupéré à J2 en post-partum. Les dosages de l’apeline dans le plasma et dans le colostrum étaient réalisés par ELISA. L’expression placentaire de l’apeline et d’APJ était étudiée par RT-PCR quantitative. La sécrétion placentaire était étudiée dans un milieu nutritif standard (DMEM) ainsi qu’en présence d’insuline (50nM) ou d’angiotensine II (AT2, 1nM). Résultats:Modèle murin : Après 3 mois de régime, les souris HF étaient obèses et intolérantes aux hydrates de carbone. Il n’y avait pas de différence d’apelinémie à jeun entre les souris T et HF hors gestation. Les placentas des souriceaux HF avaient un poids supérieur à ceux des portées T (P=0.006). Il y avait au cours de la gestation une diminution de l’apelinémie dans les 2 groupes en fin de gestation, de façon plus importante dans le groupe HF que dans le groupe Témoin (P =0.01). Chez les souris obèses, il y avait une augmentation de l’insulinorésistance en fin de gestation par rapport au groupe T (P<0.05). L’expression placentaire de l’apeline et d’APJ était augmentée dans les placentas de souris obèses. Etude chez l’humain (étude OB-APE) : L’apelinémie maternelle était diminuée dans les groupes O et ODG en comparaison avec le groupe N aux 3 temps de l’étude. L’apelinémie néonatale était également diminuée dans ces mêmes groupes. Les concentrations en apeline dans le colostrum étaient à l’inverse plus élevées dans les groupes O et ODG que dans le groupe N (P = 0,007 et P = 0,05 respectivement). Ex-vivo, la sécrétion placentaire était diminuée dans les groupes O et ODG en comparaison avec le groupe N. L’ajout d’insuline dans le milieu entrainait une augmentation de la sécrétion d’apeline, alors que l’ajout d’AT2 aboutissait à une diminution de cette sécrétion. L’expression placentaire de l’ARNm d’APJ était plus importante dans les placentas de femmes obèses que chez patientes d’IMC normal (N) [...] / Obesity is a major public health problem and is constantly increasing. Obesity alters the adipokines’ secretion, such as apeline. Apeline is involved in various functions, such as energy metabolism regulating. During pregnancy, the apelinergic system seems to be crucial for fetal development. The apelinergic system in obese pregnant women has never been studied before. The aim of this thesis was to verify whether the apelinergic system is modified in case of obesity in pregnant women, first by an experimental approach on an obese and insulin-resistant mouse model and then by a translational approach to the human (OB-APE study). Material and methods : Murine model: 40 female mice were divided into 2 groups: Control (C, n = 20) and High Fat (HF, n = 20). After 10 weeks of diet, mice were mated. Samples were taken at E6.5, E12.5 and E18.5. Mice were sacrificed by decapitation at E18.5 and blood samples were collected. Fetuses and placentas were collected after cesarean section and weighed. Fasting blood glucose, insulinaemia, maternal and fetal apelinemia were measured. At E18.5, blood samples of fetuses were collected and placentas were frozen and stored at -80°C. Human model (OB-APE study) : Prospective and comparative study conducted in Jeanne de Flandre maternity (Lille, France) between May 2016 and July 2017. Patients were divided into 3 groups: group N (normal, n=30), group O (obese, n=30) and group ODG (obese with diabetes mellitus, n=30). The maternal plasma samples were obtained at 3 different times: at the end of pregnancy (35-40 weeks of gestation), at delivery and at day 2 in postpartum, as well as a neonatal umbilical cord sampling. Placental fragments were collected at delivery and colostrum was recovered on day 2 in postpartum. The measures of apelin concentrations in plasma and colostrum were performed by ELISA. The placental expression of apelin and APJ was studied by quantitative RT-PCR. Placental secretion was studied in a standard nutrient medium (DMEM) as well as in presence of insulin (50nM) or angiotensin II (AT2, 1nM). Results: Murine model: After 3 months of diet, HF mice were obese and intolerant to carbohydrates. There was no significant difference in fasted apelinemia between non-pregnant T and HF mice. The placentas of HF mice were heavier than controls (P=0.006). There was an increase in apelinemia at E12.5 in the 2 groups (P<0.05), higher in the group HF (4.89 ± 1.18 ng/mL, vs 2.44 ± 0.42 ng/mL, P<0.001). In obese mice, there was an increase in insulin-resistance at the end of pregnancy compared to the group T (P<0.05). The placental expression of apelin and APJ was increased in obese mice. Human model (OB-APE study) : Maternal apelinemia was decreased in the O and ODG groups in comparison with the N group at the 3 times of the study. Neonatal apelinemia was also decreased in these groups. The apelin concentrations in colostrum were higher in the groups O and ODG than in the group N (P=0.007 and P=0.05 respectively). Ex-vivo, placental secretion of apelin was decreased in the groups O and ODG compared to the group N. The addition of insulin in the medium led to an increase in apelin secretion, whereas the addition of AT2 led to a diminution of this secretion. Placental expression of APJ mRNA was greater in placentas of obese women than in normal (N) patients [...]

Les modèles d'évaluation génétique des caractères de production laitière et de comptages cellulaires chez les bovins ont considérablement évolué depuis 10 ans. La plupart des pays ont mis en place (Allemagne, Canada, Danemark, Italie, Nouvelle-Zélande, Pays-Bas