scholarly journals Mitochondrial energy metabolism in a model of undernutrition induced by dexamethasone

2003 ◽  
Vol 90 (5) ◽  
pp. 969-977 ◽  
Author(s):  
Jean-François Dumas ◽  
Gilles Simard ◽  
Damien Roussel ◽  
Olivier Douay ◽  
Françoise Foussard ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Treated Group ◽  
Liver Mitochondria ◽  
Proton Leak ◽  
Thermodynamic Efficiency ◽  
Liver Mass ◽  
Mitochondrial Energy Metabolism ◽  
Thermodynamic Coupling ◽  
And Control ◽  
Complex Activities

The present investigation was undertaken to evaluate whether mitochondrial energy metabolism is altered in a model of malnutrition induced by dexamethasone (DEX) treatment (1·5mg/kg per d for 5d). The gastrocnemius and liver mitochondria were isolated from DEX-treated, pair-fed (PF) and control (CON) rats. Body weight was reduced significantly more in the DEX-treated group (−16%) than in the PF group (−9%). DEX treatment increased liver mass (+59% v. PF, +23% v. CON) and decreased gastrocnemius mass. Moreover, in DEX-treated rats, liver mitochondria had an increased rate of non-phosphorylative O2 consumption with all substrates (approximately +42%). There was no difference in enzymatic complex activities in liver mitochondria between rat groups. Collectively, these results suggest an increased proton leak and/or redox slipping in the liver mitochondria of DEX-treated rats. In addition, DEX decreased the thermodynamic coupling and efficiency of oxidative phosphorylation. We therefore suggest that this increase in the proton leak and/or redox slip in the liver is responsible for the decrease in the thermodynamic efficiency of energy conversion. In contrast, none of the variables of energy metabolism determined in gastrocnemius mitochondria was altered by DEX treatment. Therefore, it appears that DEX specifically affects mitochondrial energy metabolism in the liver.

Kinetics and control of oxidative phosphorylation in rat liver mitochondria after chronic ethanol feeding

2000 ◽  
Vol 349 (2) ◽  
pp. 519-526 ◽  
Author(s):  
Ausra MARCINKEVICIUTE ◽  
Vida MILDAZIENE ◽  
Sara CRUMM ◽  
Oleg DEMIN ◽  
Jan B. HOEK ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Rat Liver ◽  
Liver Mitochondria ◽  
Proton Leak ◽  
Rat Liver Mitochondria ◽  
Protonmotive Force ◽  
Compensatory Mechanisms ◽  
Mitochondrial Energy Metabolism ◽  
Ethanol Feeding ◽  
And Control

Changes in the kinetics and regulation of oxidative phosphorylation were characterized in isolated rat liver mitochondria after 2 months of ethanol consumption. Mitochondrial energy metabolism was conceptually divided into three groups of reactions, either producing protonmotive force (∆p) (the respiratory subsystem) or consuming it (the phosphorylation subsystem and the proton leak). Manifestation of ethanol-induced mitochondrial malfunctioning of the respiratory subsystem was observed with various substrates; the respiration rate in State 3 was inhibited by 27±4% with succinate plus amytal, by 20±4% with glutamate plus malate, and by 17±2% with N,N,Nʹ,Nʹ-tetramethyl-p-phenylenediamine/ascorbate. The inhibition of the respiratory activity correlated with the lower activities of cytochrome c oxidase, the bc1 complex, and the ATP synthase in mitochondria of ethanol-fed rats. The block of reactions consuming the ∆p to produce ATP (the phosphorylating subsystem) was suppressed after 2 months of ethanol feeding, whereas the mitochondrial proton leak was not affected. The contributions of ∆p supply (the respiratory subsystem) and ∆p demand (the phosphorylation and the proton leak) to the control of the respiratory flux were quantified as the control coefficients of these subsystems. In State 3, the distribution of control exerted by different reaction blocks over respiratory flux was not significantly affected by ethanol diet, despite the marked changes in the kinetics of individual functional units of mitochondrial oxidative phosphorylation. This suggests the operation of compensatory mechanisms, when control redistributes among the different components within the same subsystem.

scholarly journals Kinetics and control of oxidative phosphorylation in rat liver mitochondria after dexamethasone treatment

2004 ◽  
Vol 382 (2) ◽  
pp. 491-499 ◽  
Author(s):  
Damien ROUSSEL ◽  
Jean-François DUMAS ◽  
Gilles SIMARD ◽  
Yves MALTHIÈRY ◽  
Patrick RITZ
Keyword(s):  
Membrane Potential ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Liver Mitochondria ◽  
Energetic Cost ◽  
Proton Leak ◽  
Mitochondrial Bioenergetics ◽  
Dexamethasone Treatment ◽  
And Control

The present investigation was undertaken in order to evaluate the contributions of ATP synthesis and proton leak reactions to the rate of active respiration of liver mitochondria, which is altered following dexamethasone treatment (1.5 mg/kg per day for 5 days). We applied top-down metabolic control analysis and its extension, elasticity analysis, to gain insight into the mechanisms of glucocorticoid regulation of mitochondrial bioenergetics. Liver mitochondria were isolated from dexamethasone-treated, pair-fed and control rats when in a fed or overnight fasted state. Injection of dexamethasone for 5 days resulted in an increase in the fraction of the proton cycle of phosphorylating liver mitochondria, which was associated with a decrease in the efficiency of the mitochondrial oxidative phosphorylation process in liver. This increase in proton leak activity occurred with little change in the mitochondrial membrane potential, despite a significant decrease in the rate of oxidative phosphorylation. Regulation analysis indicates that mitochondrial membrane potential homoeostasis is achieved by equal inhibition of the mitochondrial substrate oxidation and phosphorylation reactions in rats given dexamethasone. Our results also suggest that active liver mitochondria from dexamethasone-treated rats are capable of maintaining phosphorylation flux for cellular purposes, despite an increase in the energetic cost of mitochondrial ATP production due to increased basal proton permeability of the inner membrane. They also provide a complete description of the effects of dexamethasone treatment on liver mitochondrial bioenergetics.

Influence of intensity of food restriction on skeletal muscle mitochondrial energy metabolism in rats

2006 ◽  
Vol 291 (3) ◽  
pp. E460-E467 ◽  
Author(s):  
Gyasi Johnson ◽  
Damien Roussel ◽  
Jean-François Dumas ◽  
Olivier Douay ◽  
Yves Malthièry ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Energy Metabolism ◽  
Food Restriction ◽  
Metabolic Adaptation ◽  
Proton Leak ◽  
Mitochondrial Energy Metabolism ◽  
Respiration Rates ◽  
Mitochondrial Functions ◽  
Mitochondrial Adaptation ◽  
Putative Mechanism

Variable durations of food restriction (FR; lasting weeks to years) and variable FR intensities are applied to animals in life span-prolonging studies. A reduction in mitochondrial proton leak is suggested as a putative mechanism linking such diet interventions and aging retardation. Early mechanisms of mitochondrial metabolic adaptation induced by FR remain unclear. We investigated the influence of different degrees of FR over 3 days on mitochondrial proton leak and mitochondrial energy metabolism in rat hindlimb skeletal muscle. Animals underwent 25, 50, and 75% and total FR compared with control rats. Proton leak kinetics and mitochondrial functions were investigated in two mitochondrial subpopulations, intermyofibrillar (IMF) and subsarcolemmal (SSM) mitochondria. Regardless of the degree of restriction, skeletal muscle mass was not affected by 3 days of FR. Mitochondrial basal proton conductance was significantly decreased in 50% restricted rats in both mitochondrial subpopulations (46 and 40% for IMF and SSM, respectively) but was unaffected in other groups compared with controls. State 3 and uncoupled state 3 respiration rates were decreased in SSM mitochondria only for 50% restricted rats when pyruvate + malate was used as substrate (−34.5 and −38.9% compared with controls, P < 0.05). IMF mitochondria respiratory rates remained unchanged. Three days of FR, particularly at 50% FR, were sufficient to lower mitochondria energetic metabolism in both mitochondrial populations. Our study highlights an early step in mitochondrial adaptation to FR and the influence of the severity of restriction on this adaptation. This step may be involved in an aging-retardation process.

POSSIBILITY TO REDUCE THROMBOCYTOPENIA AFTER CHEMORADIOTHERAPY IN ONCOLOGICAL PATIENTS

2017 ◽  
Vol 63 (3) ◽  
pp. 466-469
Author(s):  
Luiza Korytova ◽  
Aleksey Meshechkin ◽  
Oleg Korytov ◽  
V. Krasnikova
Keyword(s):  
Combined Treatment ◽  
Treated Group ◽  
Median Number ◽  
Blood Analysis ◽  
Control Group ◽  
Level Control ◽  
Normal Range ◽  
Oncological Patients ◽  
Level Increase ◽  
And Control

Objective was to establish efficiency of sodium nucleospermat in correcting thrombocytopenia after chemoradiotherapy in oncological patients. Methods and materials. The study included data on 32 patients that had undergone combined treatment from January till May 2016. After detecting thrombocytopenia patients were randomized into two groups (16 patients in each): treated group, where patients received sodium nucleospermat, and control group, where sodium nucleospermat was not used. Thrombocyte level control was done on 5th, 10th and 15th day after treatment was over. Results and discussion. All 16 patients showed positive dynamics in increasing thrombocyte level after Sodium nucleospermat injection course was finished. This was proven by first (5th day) blood analysis. On average thrombocyte level after sodium nucleospermat treatment has risen to normal, at 161х109/1. Only 3 patients from this group had to pause radiotherapy for 5 days. Control group patients, which did not receive sodium nucleospermat, showed evidence of thrombocyte level recovery by 10th day only. On average thrombocyte level increase was insignificant, and median number was 111*109/l. Low thrombocyte level was main reason to pause radiotherapy for 11 (69%) patients in control group. Conclusion. Sodium nucleospermat allowed raising thrombocyte level to the lower normal range, which surpassed by 40%-50% in control group patients. Use of sodium nucleospermat did not show any cases of allergic reactions, toxicity or complications in oncological patients.

Therapeutic Approaches Using Riboflavin in Mitochondrial Energy Metabolism Disorders

2016 ◽  
Vol 17 (13) ◽  
pp. 1527-1534 ◽  
Author(s):  
Bárbara J. Henriques ◽  
Tânia G. Lucas ◽  
Cláudio M. Gomes
Keyword(s):  
Energy Metabolism ◽  
Therapeutic Approaches ◽  
Mitochondrial Energy Metabolism

Mitochondrial energy metabolism is negatively regulated by cannabinoid receptor 1 in intact human epidermis

2020 ◽  
Vol 29 (7) ◽  
pp. 616-622 ◽  
Author(s):  
Attila Oláh ◽  
Majid Alam ◽  
Jérémy Chéret ◽  
Nikolett Gréta Kis ◽  
Zoltán Hegyi ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Cannabinoid Receptor ◽  
Human Epidermis ◽  
Cannabinoid Receptor 1 ◽  
Mitochondrial Energy Metabolism

scholarly journals Effects of Camu-Camu (Myrciaria dubia) Powder on the Physicochemical and Kinetic Parameters of Deteriorating Microorganisms and Salmonella enterica Subsp. enterica Serovar Typhimurium in Refrigerated Vacuum-Packed Ground Beef

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 252
Author(s):  
Jorge Luiz da Silva ◽  
Vasco Cadavez ◽  
José M. Lorenzo ◽  
Eduardo Eustáquio de Souza Figueiredo ◽  
Ursula Gonzales-Barron
Keyword(s):  
Ground Beef ◽  
Treated Group ◽  
B Value ◽  
Kinetics Parameters ◽  
Psychrotrophic Bacteria ◽  
Color Changes ◽  
A Value ◽  
Spoilage Bacteria ◽  
Serovar Typhimurium ◽  
And Control

This study aims to evaluate the effects of camu-camu powder (CCP), Amazonian berry fruit with documented bioactive properties, physicochemical meat parameters, and the growth kinetics parameters of S. enterica ser. Typhimurium, psychrotrophic bacteria (PSY), and lactic acid bacteria (LAB) in vacuum-packed ground beef. Batches of ground beef were mixed with 0.0%, 2.0%, 3.5%, and 5.0% CCP (w/w), vacuum-packed as 10 g portions, and stored at 5 °C for 16 days. Centesimal composition analyses (only on the initial day), pH, TBARS, and color were quantified on storage days 1, 7, and 15, while PSY and LAB were counted on days 0, 3, 6, 9, 13, and 16. Another experiment was conducted with the same camu-camu doses by inoculating S. enterica ser. Typhimurium microbial kinetic curves were modeled by the Huang growth and Weibull decay models. CCP decreased TBARS in beef from 0.477 to 0.189 mg MDA·kg−1. No significant differences in meat pH between treated and control samples were observed on day 15. CCP addition caused color changes, with color a* value decreases (from 14.45 to 13.44) and color b* value increases (from 17.41 to 21.25), while color L* was not affected. Higher CCP doses caused progressive LAB growth inhibition from 0.596 to 0.349 log CFU·day−1 at 2.0% and 5.0% CCP, respectively. Similarly, PSY growth rates in the treated group were lower (0.79–0.91 log CFU·day−1) compared to the control (1.21 log CFU·day−1). CCP addition at any of the investigated doses produced a steeper S. enterica ser. Typhimurium inactivation during the first cold storage day, represented by Weibull’s concavity α shape parameter, ranged from 0.37 to 0.51, in contrast to 1.24 for the control. At the end of the experiment, however, S. enterica ser. Typhimurium counts in beef containing CCP were not significantly different (p < 0.05) from the control. Although CCP affects bacterial kinetics, it does not protect ground beef against spoilage bacteria and Salmonella to the same degree it does against lipid peroxidation.

scholarly journals Mitochondrial P2X7 receptor localization modulates energy metabolism enhancing physical performance

Function ◽  
2021 ◽  
Author(s):  
Alba Clara Sarti ◽  
Valentina Vultaggio-Poma ◽  
Simonetta Falzoni ◽  
Sonia Missiroli ◽  
Anna Lisa Giuliani ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Physical Fitness ◽  
P2x7 Receptor ◽  
Human Fibroblasts ◽  
Atp Synthesis ◽  
Heart Tissue ◽  
Mitochondrial Potential ◽  
Mitochondrial Energy Metabolism ◽  
Microglia Cell ◽  
Basal Expression

Abstract Basal expression of the P2X7 receptor (P2X7R) improves mitochondrial metabolism, ATP synthesis and overall fitness of immune and non-immune cells. We investigated P2X7R contribution to energy metabolism and subcellular localization in fibroblasts (mouse embryo fibroblasts and HEK293 human fibroblasts), mouse microglia (primary brain microglia and the N13 microglia cell line), and heart tissue. The P2X7R localizes to mitochondria, and its lack a) decreases basal respiratory rate, ATP-coupled respiration, maximal uncoupled respiration, resting mitochondrial potential, mitochondrial matrix Ca2+ level, b) modifies expression pattern of oxidative phosphorylation (OxPhos) enzymes, and c) severely affects cardiac performance. Hearts from P2rx7-deleted versus WT mice are larger, heart mitochondria smaller, and stroke volume (SV), ejection fraction (EF), fractional shortening (FS) and cardiac output (CO), are significantly decreased. Accordingly, physical fitness of P2X7R-null mice is severely reduced. Thus, the P2X7R is a key modulator of mitochondrial energy metabolism and a determinant of physical fitness.

Protective effects of lipoic acid against acrylamide-induced neurotoxicity: involvement of mitochondrial energy metabolism and autophagy

2017 ◽  
Vol 8 (12) ◽  
pp. 4657-4667 ◽  
Author(s):  
Ge Song ◽  
Zhigang Liu ◽  
Luanfeng Wang ◽  
Renjie Shi ◽  
Chuanqi Chu ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Lipoic Acid ◽  
Redox Status ◽  
Protective Effects ◽  
Mitochondrial Energy Metabolism

Lipoic acid (LA) suppressed acrylamide (ACR)-induced inflammation, redox status disturbance, autophagy, and apoptosis mediated by mitochondria in the SH-SY5Y cells.

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