7 research outputs found
SUN-PO316: Impact of Protein Intake and High-Fat Diet on Muscle Protein Synthesis and Lipid Infiltration in Relation to Aging in Rats
Part of special issue: Abstracts of the 41st ESPEN Congress, Krakow, Poland, 31 Augustâ3 September, 2019International audienceRationale: Ectopic lipid deposition impairs muscle anabolic responseespecially during aging. We hypothesized that the anabolic efficiencyof dietary protein in skeletal muscle might be affected by high-fat diet.The objective of the study was to investigate muscle protein synthesisin response totwolevels of protein intake combined totwo levels of fatintake. Methods: Two groups of sixty adult and forty-nine old male Wistarrats were randomly divided into four groups: isocaloric standard diet (12% protein, 14% lipid, as STD12); isocaloric standard (high-protein)diet (25% protein, 14% lipid, STD25); hypercaloric high-fat (normal-protein) diet (12% protein, 45% lipid, HFD12); and hypercaloric high-fat (high-protein) diet (25% protein, 45% lipid, HFD25). The nutritionalintervention lasted 10 weeks. The fractional synthesis (FSR) andabsolute synthesis rates (ASR) of mixed muscle proteins werecalculated using isotopically labelled13C-Valine incorporation intibialis anterior (TA). Muscle lipid content was assessed usingchromatography method. Results: Rats in the high-fat diet groups self-limited their food intake,so that energy intake was not different among the groups. Regardlessof dietary intervention, TAweight was lower in old groups compared totheir adult counterparts (all p values Conclusions: Aging is characterized by reduced muscleweight despiteincreased FSR, suggesting specific alterations in the nutritionalregulation of muscle protein turnover. In isocaloric conditions, higherprotein intake modulates muscle lipid infiltration, without improvingage-related anabolic resistance in old rats fed a high-fat diet
L'invalidation génétique des protéines 4E-BP1/2 chez la souris induit l'insulino-résistance et une lipotoxicité au niveau musculaire
National audiencemTOR (mammalian Target of rapamycin) est un noeud mĂ©tabolique qui en rĂ©ponse aux nutriments et facteurs de croissance rĂ©gule de nombreux processus cellulaires. Une suractivation de mTOR est souvent observĂ©e dans les tissus de patients obĂšses ou les modĂšles animaux dâobĂ©sitĂ© et associĂ©e Ă lâinsulinorĂ©sistance. Cependant, le rĂŽle prĂ©cis des diffĂ©rentes cibles de mTOR dans lâinstallation des dĂ©sordres mĂ©taboliques est encore peu explorĂ©. Chez la souris, la dĂ©lĂ©tion des protĂ©ines 4EBP1 et 4EBP2 (cibles de mTOR) au niveau du corps entier provoque une sensibilitĂ© accrue Ă lâinduction de lâobĂ©sitĂ© en favorisant lâadipogenĂšse et lâinsulino-rĂ©sistance. Lâobjectif de cette Ă©tude Ă©tait de dĂ©terminer chez la souris lâimpact de la dĂ©lĂ©tion de 4EBP1 et 4EBP2 sur la lipotoxicitĂ© musculaire en rĂ©ponse Ă un rĂ©gime riche en graisses. Des souris sauvages (WT) et invalidĂ©es pour les protĂ©ines 4EBP1 et 2 (4EBP1/2 Double KO, DKO) ont reçu un rĂ©gime standard (STD. 3,79kcal/g de rĂ©gime) ou riche en graisses (HFD. 4,60kcal/g) pendant 20 semaines. A la fin de ce rĂ©gime des tests ITT et ipGTT ont Ă©tĂ© rĂ©alisĂ©s pour mesurer le degrĂ© dâinsulinorĂ©sistance et de tolĂ©rance au glucose. Les contenus intramusculaires en lipides, cĂ©ramides et sphingomyĂ©lines ont Ă©tĂ© mesurĂ©s par chromatographie gazeuse et HPLC-MS afin de caractĂ©riser les atteintes lipidiques musculaires. Lâexpression des gĂšnes impliquĂ©s dans le transport des acides gras, le mĂ©tabolisme des lipides et la bĂȘta-oxydation a Ă©tĂ© mesurĂ©e dans le muscle par PCR quantitative. Lâexpression dâATGL a Ă©tĂ© mesurĂ©e par western blot et lâactivitĂ© ATGL mesurĂ©e. Les rĂ©sultats ont Ă©tĂ© analysĂ©s par ANOVA Ă 2 voies. Le rĂ©gime HFD induit une prise de poids chez les souris WT et DKO, avec une prise de masse musculaire plus importante chez les souris DKO (p<0.01). Les souris DKO dĂ©veloppent Ă©galement une insulinorĂ©sistance et une intolĂ©rance au glucose plus importante que les souris WT (p<0.01). Le rĂ©gime HFD induit une accumulation intramusculaire similaire des TG chez les souris WT et DKO, et une accumulation plus importante de DG (+44%, p<0.01), cĂ©ramides (+22%, p<0.05), et sphingomyĂ©lines (+30%, p<0.01) chez les souris DKO. Lâexpression protĂ©ique et lâactivitĂ© ATGL ne sont pas modifiĂ©es en rĂ©gime HF quel que soit le gĂ©notype. Lâaccumulation intramusculaire de lipides est associĂ©e Ă une augmentation de lâexpression de gĂšnes impliquĂ©s dans le transport des AG (i.e. FATP, CD36), le mĂ©tabolisme des TG (GPAT1, AGPAT1 et DGAT1) et la bĂȘta-oxydation (MCAD et CPT1B). Lâinvalidation de 4EBP1 et 4EBP2 favorisent lâaccumulation ectopique de lipides au niveau musculaire en rĂ©ponse Ă un rĂ©gime riche en graisses. Cet effet ne semble pas ĂȘtre dĂ» Ă une modification de lâactivitĂ© de la lipase ATGL mais serait associĂ© Ă une augmentation de la captation des AG et Ă des modifications du mĂ©tabolisme des lipide
EXPERIMENTAL INVESTIGATION OF GLUED LAMINATED TIMBER BEAM-TO-BEAM CONNECTION / KLIJUOTOSIOS MEDIENOS SIJOS ELEMENTĆČ TARPUSAVIO JUNGTIES EKSPERIMENTINIS TYRIMAS
El ambiente entre representaciĂłn y ecologĂa - Un estudio de caso en Guatemala, siglo XIX The environment: between representation and ecology - A case study of Guatemala, 19th century
<abstract language="por">A Guatemala - onde a cultura do cafĂ© assumiu papel relevante - foi alvo de intensa idealização de sua natureza, ao mesmo tempo em que foi exaltada como uma nação essencialmente agrĂcola. Tais imagens se construĂram tanto sobre bases naturais como sobre representa çÔes sociais e histĂłricas. Muitos estudos apontam a existĂȘncia de duas macro-regiĂ”es homogĂȘneas no seu territĂłrio. Entretanto, cada uma delas apresenta uma composição ecolĂłgica muito mais variada do que se supĂ”e tradicionalmente, o que se configura como um dos principais fatores de compreensĂŁo da constituição histĂłrica das regiĂ”es de plantio do cafĂ© naquele paĂs.<br>Guatemala - where the culture of coffee became relevant - was the target of intense idealization of its nature, at the same time that it was exalted as an essentially agricultural nation. Such images were built upon natural bases as well as upon social and historical representations. Many studies point to the existence of two homogeneous macroregions in the territory. However, each one of them presents an ecological composition much more varied than is traditionally supposed, which is one of the main factors for understanding the historical constitution of coffee plantation regions in that country