50 research outputs found
Effects of Whey Protein on Skeletal Muscle Microvascular and Mitochondrial Plasticity Following 10-Weeks of Exercise Training in Men with Type-2 Diabetes
Copyright remains with the author(s) or their institution(s).Abstract
Skeletal muscle microvascular dysfunction and mitochondrial rarefaction feature in type 2 diabetes mellitus (T2DM) linked to low tissue glucose disposal rate (GDR). Exercise training and milk protein supplementation independently promote microvascular and metabolic plasticity in muscle associated with improved nutrient delivery, but combined effects are unknown. In a randomised-controlled trial, 24 men (55.6 y, SD 5.7) with T2DM ingested whey protein drinks (protein/carbohydrate/fat: 20/10/3 g; WHEY) or placebo (carbohydrate/fat: 30/3 g; CON) before/after 45 mixed-mode intense exercise sessions over 10 weeks, to study effects on insulin-stimulated (hyperinsulinemic clamp) skeletal-muscle microvascular blood flow (mBF) and perfusion (near-infrared spectroscopy), and histological, genetic, and biochemical markers (biopsy) of microvascular and mitochondrial plasticity. WHEY enhanced insulin-stimulated perfusion (WHEY-CON 5.6%; 90% CI −0.1, 11.3), while mBF was not altered (3.5%; −17.5, 24.5); perfusion, but not mBF, associated (regression) with increased GDR. Exercise training increased mitochondrial (range of means: 40%–90%) and lipid density (20%–30%), enzyme activity (20%–70%), capillary:fibre ratio (∼25%), and lowered systolic (∼4%) and diastolic (4%–5%) blood pressure, but without WHEY effects. WHEY dampened PGC1α −2.9% (90% compatibility interval: −5.7, −0.2) and NOS3 −6.4% (−1.4, −0.2) expression, but other messenger RNA (mRNA) were unclear. Skeletal muscle microvascular and mitochondrial exercise adaptations were not accentuated by whey protein ingestion in men with T2DM.
ANZCTR Registration Number: ACTRN12614001197628.
Novelty:
• Chronic whey ingestion in T2DM with exercise altered expression of several mitochondrial and angiogenic mRNA.
• Whey added no additional benefit to muscle microvascular or mitochondrial adaptations to exercise.
• Insulin-stimulated perfusion increased with whey but was without impact on glucose disposal.
Résumé
Le dysfonctionnement microvasculaire du muscle squelettique et la raréfaction mitochondriale caractérisant le diabète de type 2 (« T2DM ») sont liés à un faible taux d’élimination du glucose tissulaire (« GDR »). L’entraînement physique et la supplémentation en protéines du lait favorisent indépendamment la plasticité microvasculaire et métabolique dans le muscle; cette plasticité est associée à une amélioration de l’apport de nutriments, mais les effets combinés sont inconnus. Dans un essai contrôlé randomisé, 24 hommes (55,6 ans, SD 5,7) aux prises avec le T2DM consomment des boissons protéinées de lactosérum (protéines / glucides / lipides: 20/10/3 g; « WHEY ») ou un placebo (glucides / lipides: 30/3 g; « CON ») avant / après 45 séances d’exercice intense en mode mixte sur 10 semaines, et ce, pour examiner les effets sur le flux sanguin microvasculaire (« mBF ») et la perfusion (spectroscopie proche infrarouge) stimulés par l’insuline (clamp hyperinsulinémique), des variables histologiques, génétiques et des marqueurs biochimiques (biopsie) de la plasticité microvasculaire et mitochondriale. WHEY améliore la perfusion stimulée par l’insuline (WHEY-CON 5,6 %; IC 90 % −0,1, 11,3), tandis que le mBF n’est pas modifié (3,5 %; −17,5, 24,5); la perfusion, mais pas le mBF, est associée (régression) à une augmentation du GDR. L’entraînement à l’exercice augmente la densité mitochondriale (gamme de moyennes: 40-90 %) et lipidique (20−30 %), l’activité enzymatique (20−70 %), le ratio capillaire: fibre (∼25 %) et diminue les pressions systolique (∼4 %) et diastolique (4−5 %), mais sans effets de WHEY. WHEY amortit l’expression de PGC1α −2,9 % (intervalle de compatibilité de 90 % : −5,7, −0,2) et NOS3 −6,4 % (−1,4, −0,2), mais les autres ARN messager (ARNm) ne sont pas clairs. Les adaptations microvasculaires et mitochondriales des muscles squelettiques causées par l’entraînement physique ne sont pas accentuées par la consommation de protéines de lactosérum chez les hommes aux prises avec le T2DM.
Numéro d’enregistrement ANXCTR : ACTRN12614001197628. [Traduit par la Rédaction]
Les nouveautés:
• La consommation prolongée de lactosérum en présence de T2DM combinée à l’entraînement physique modifie l’expression de plusieurs ARNm mitochondriaux et angiogéniques.
• Le lactosérum n’ajoute aucun avantage supplémentaire aux adaptations microvasculaires ou mitochondriales musculaires à l’exercice physique.
• La perfusion stimulée par l’insuline augmente avec le lactosérum mais n’a pas d’impact sur l’élimination du glucose.falseGaffney, Kim Lucero, Adam Macartney-Coxson, Donia Clapham, Jane Whitfield, Patricia Palmer, Barry Wakefield, StJohn Faulkner, James Stoner, Lee Rowlands, David Stephen eng Canada Appl Physiol Nutr Metab. 2021 Feb 16. doi: 10.1139/apnm-2020-0943.
Skeletal muscle microvascular dysfunction and mitochondrial rarefaction feature in type-2 diabetes mellitus (T2DM) linked to low tissue glucose disposal rate (GDR). Exercise training and milk protein supplementation independently promote microvascular and metabolic plasticity in muscle associated with improved nutrient delivery, but combined effects are unknown. In a randomised-controlled trial, 24 men (55.6 y, SD5.7) with T2DM ingested whey protein drinks (protein/carbohydrate/fat: 20/10/3 g; WHEY) or placebo (carbohydrate/fat: 30/3 g; CON) before/after 45 mixed-mode intense exercise sessions over 10 weeks, to study effects on insulin-stimulated (hyperinsulinemic clamp) skeletal-muscle microvascular blood flow (mBF) and perfusion (near-infrared spectroscopy), and histological, genetic, and biochemical markers (biopsy) of microvascular and mitochondrial plasticity. WHEY enhanced insulin-stimulated perfusion (WHEY-CON 5.6%; 90%CI -0.1, 11.3), while mBF was not altered (3.5%; -17.5, 24.5); perfusion, but not mBF, associated (regression) with increased GDR. Exercise training increased mitochondrial (range of means: 40-90%) and lipid density (20-30%), enzyme activity (20-70%), capillary:fiber ratio (~25%), and lowered systolic (~4%) and diastolic (4-5%) blood pressure, but without WHEY effects. WHEY dampened PGC1alpha -2.9% (90%CI -5.7, -0.2) and NOS3 -6.4% (-1.4, -0.2) expression, but other mRNA were unclear. Skeletal muscle microvascular and mitochondrial exercise adaptations were not accentuated by whey protein ingestion in men with T2DM. Clinical Trial Registration Number: ACTRN12614001197628 Novelty Bullets: * Chronic whey ingestion in T2DM with exercise altered expression of several mitochondrial and angiogenic mRNA. * Whey added no additional benefit to muscle microvascular or mitochondrial adaptations to exercise. * Insulin-stimulated perfusion increased with whey but was without impact on glucose disposal
Quantitative Computed Tomography in COPD: Possibilities and Limitations
Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease that is characterized by chronic airflow limitation. Unraveling of this heterogeneity is challenging but important, because it might enable more accurate diagnosis and treatment. Because spirometry cannot distinguish between the different contributing pathways of airflow limitation, and visual scoring is time-consuming and prone to observer variability, other techniques are sought to start this phenotyping process. Quantitative computed tomography (CT) is a promising technique, because current CT technology is able to quantify emphysema, air trapping, and large airway wall dimensions. This review focuses on CT quantification techniques of COPD disease components and their current status and role in phenotyping COPD
Protective management of trees against debarking by deer negatively impacts bryophyte diversity
When wildlife populations become too large, they impact other flora and fauna within the ecosystems that they inhabit. For example, the recent rise in population numbers of sika deer in Japan has led to the stripping of bark from tree overstories in forested areas. This has led to protective management actions, such as wrapping the trunks of trees in wire mesh. The present study investigates the impact of this management action on epiphytic diversity at Mt. Ohdaigahara, which is one of the hotspots for bryophyte diversity in Japan. The correlation between the diversity of epiphytic bryophytes and environmental variables was examined, including the presence/absence of wire mesh protection. A generalized linear model showed that species richness and bryophyte cover was significantly correlated with both tree diameter (at 1.5 m height) and tree density (P < 0.01), but negatively correlated with wire mesh protection. Inductively coupled plasma-mass spectrometry analysis showed a significant 3- to 6-fold higher concentration of zinc in bryophytes occupying tree bark under wire mesh protection than for those without wire mesh. Hence, the high sensitivity of bryophytes to zinc accumulation, as a result of toxicity caused by galvanized iron mesh, has led to the loss of species richness and bryophyte cover on tree trunks. Furthermore, other heavy metals found in wire mesh may also contribute to the negative effect on bryophytes. Therefore, to establish best practices for biodiversity conservation that include bryophytes, materials that are free of heavy metals should be preferentially used for tree protection
Can Computed Tomography Predict Functional Benefit from Lung Volume Reduction Surgery for Emphysema?
Enhancement of forest canopy research, education, and conservation in the new millennium
Effects of Freezing and Thawing Cycles on Microbial Biomass Nitrogen and Organic Nitrogen in Alpine Meadow Soil*
Recovery of adenine-nucleotide pools in terrestrial blue-green algae after prolonged drought periods
Forecasting the Future Economic Burden of Current Adolescent Overweight: An Estimate of the Coronary Heart Disease Policy Model
Objectives. We predicted the future economic burden attributable to high rates of current adolescent overweight
