Measuring Liver Mitochondrial Oxygen Consumption and Proton Leak Kinetics to Estimate Mitochondrial Respiration in Holstein Dairy Cattle

10.3791/58387 ◽  
2018 ◽  
Author(s):  
Heidi A. Rossow ◽  
Gabriela Acetoze ◽  
John Champagne ◽  
Jon J. Ramsey
Keyword(s):  
Oxygen Consumption ◽  
Dairy Cattle ◽  
Mitochondrial Respiration ◽  
Proton Leak ◽  
Mitochondrial Oxygen Consumption

scholarly journals Relationship between Liver Mitochondrial Respiration and Proton Leak in Low and High RFI Steers from Two Lineages of RFI Angus Bulls

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
G. Acetoze ◽  
K. L. Weber ◽  
J. J. Ramsey ◽  
H. A. Rossow
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Mitochondrial Respiration ◽  
Dry Matter ◽  
Genetic Test ◽  
Bodyweight Gain ◽  
Dry Matter Intake ◽  
Proton Leak ◽  
Adaptation Period ◽  
Mitochondrial Oxygen Consumption

The objective of this research is to evaluate liver mitochondrial oxygen consumption and proton leak kinetics in progeny from two lineages of Angus bulls with high and low residual feed intake (RFI). Two Angus bulls were selected based on results from a genetic test for RFI and were used as sires. Eight offspring at 10-11 months of age from each sire were housed in individual pens for 70–105 days following a diet adaptation period of 14 days. Progeny of the low RFI sire had 0.57 kg/d (P=0.05) lower average RFI than progeny of the high RFI sire. There was no difference in dry matter intake between low and high RFI steers, but low RFI steers gained more body weight (P=0.02) and tended to have higher average daily gains (P=0.07). State 3 and State 4 respiration, RCR, and proton leak did not differ between high and low RFI steers (P=0.96, P=0.81, P=0.93, and P=0.88, resp.). Therefore, the increase in bodyweight gain which distinguished the low RFI steers from the high RFI steers may be associated with other metabolic mechanisms that are not associated with liver mitochondrial respiration and proton leak kinetics.

Mitochondrial respiration in muscle and liver from cold-acclimated hypothyroid rats

2003 ◽  
Vol 95 (4) ◽  
pp. 1584-1590 ◽  
Author(s):  
Angel A. Zaninovich ◽  
Inés Rebagliati ◽  
Marcela Raíces ◽  
Conrado Ricci ◽  
Karl Hagmüller
Keyword(s):  
Adipose Tissue ◽  
Oxygen Consumption ◽  
Brown Adipose Tissue ◽  
Cold Acclimation ◽  
Cold Exposure ◽  
Mitochondrial Respiration ◽  
Mitochondrial Oxygen Consumption ◽  
Normal Body ◽  
Thyroid Ablation ◽  
Brown Adipose

The effects of long-term cold exposure on muscle and liver mitochondrial oxygen consumption in hypothyroid and normal rats were examined. Thyroid ablation was performed after 8-wk acclimation to 4°C. Hypothyroid and normal controls remained in the cold for an additional 8 wk. At the end of 16-wk cold exposure, all hypothyroid rats were alive and normothermic and had normal body weight. At ambient temperature (24°C), thyroid ablation induced a 65% fall in muscle mitochondrial oxygen consumption, which was reversed by thyroxine but not by norepinephrine administration. After cold acclimation was reached, suppression of thyroid function reduced muscle mitochondrial respiration by 30%, but the hypothyroid values remained about threefold higher than those in hypothyroid muscle in the warm. Blockade of β- and α1-adrenergic receptors in both hypothyroid and normal rats produced hypothermia in vivo and a fall in muscle, liver, and brown adipose tissue mitochondria respiration in vitro. In normal rats, cold acclimation enhanced muscle respiration by 35%, in liver 18%, and in brown adipose tissue 450% over values in the warm. The results demonstrate that thyroid hormones, in the presence of norepinephrine, are major determinants of thermogenic activity in muscle and liver of cold-acclimated rats. After thyroid ablation, cold-induced nonshivering thermogenesis replaced 3,5,3′-triiodothyronine-induced thermogenesis, and normal body temperature was maintained.

scholarly journals Impaired Mitochondrial Bioenergetics Function in Pediatric Chronic Overlapping Pain Conditions with Functional Gastrointestinal Disorders

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Gisela Chelimsky ◽  
Pippa Simpson ◽  
Liyun Zhang ◽  
Doug Bierer ◽  
Steve Komas ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Respiratory Chain ◽  
Mitochondrial Function ◽  
Mitochondrial Respiration ◽  
Functional Disability ◽  
Functional Gastrointestinal Disorders ◽  
Energy Generation ◽  
Proton Leak ◽  
Gastrointestinal Disorders ◽  
Reserve Capacity

Background. Fatigue is often the primary complaint of children with functional gastrointestinal disorders (FGDI) and other chronic overlapping pain disorders (COPC). The basis for this symptom remains unknown. We evaluated mitochondrial function in the white blood cells of these patients. Methods. This prospective Children’s Wisconsin IRB approved study recruited subjects aging 10–18 years from pediatric neurogastroenterology clinics and healthy comparison subjects (HC). Environmental and oxidative stressors can damage the mitochondrial respiratory chain. The known low-grade inflammation in COPC could, therefore, impact the respiratory chain and theoretically account for the disabling fatigue so often voiced by patients. Mitochondrial energy generation can be easily measured in peripheral mononuclear cells (PMC) as a general marker by the Seahorse XF96 Extracellular Flux Analyzer. We measured 5 parameters of oxygen consumption using this methodology: basal respiration (BR), ATP linked oxygen consumption (ATP-LC), maximal oxygen consumption rate (max R), spare respiratory capacity (SRC), and extracellular acidification rate (ECAR), which reflect non-electron chain energy generation through glycolysis. In health, we expect high ATP linked respiration, high reserve capacity, low proton leak, and low non-mitochondrial respiration. In disease, the proton leak typically increases, ATP demand increases, and there is decreased reserve capacity with increased non-mitochondrial respiration. Findings and clinical data were compared to healthy control subjects using a Mann–Whitney test for skewed variables, Fisher’s exact test for dichotomous variables, and regression tree for association with functional outcome (functional disability inventory, FDI). Results. 19 HC and 31 COPC showed no statistically significant difference in age. FGID, orthostatic intolerance, migraine, sleep disturbance, and chronic fatigue were present in the majority of COPC subjects. BR, ECAR, and ATP-LC rates were lower in the COPC group. The low BR and ATP-LC suggest that mitochondria are stressed with decreased ability to produce ATP. Tree analysis selected SRC as the best predictor of functional disability: patients with SRC >150 had a greater FDI (more disability) compared to patients with SRC <=150, p -value = 0.021. Conclusion. Subjects with COPC have reduced mitochondrial capacity to produce ATP. Predisposing genetic factors or reversible acquired changes may be responsible. A higher SRC best predicts disability. Since a higher SRC is typically associated with more mitochondrial reserve, the SRC may indicate an underutilized available energy supply related to inactivity, or a “brake” on mitochondrial function. Prospective longitudinal studies can likely discern whether these findings represent deconditioning, true mitochondrial dysfunction, or both.

Effect of hyperthermia and acidosis on equine skeletal muscle mitochondrial oxygen consumption

2020 ◽  
pp. 1-10
Author(s):  
M.S. Davis ◽  
M.R. Fulton ◽  
A. Popken
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Muscle Fatigue ◽  
Mitochondrial Function ◽  
Mitochondrial Respiration ◽  
Complex I ◽  
Mitochondrial Oxygen Consumption ◽  
Biochemical Basis ◽  
Complex Ii

The skeletal muscle of exercising horses develops pronounced hyperthermia and acidosis during strenuous or prolonged exercise, with very high tissue temperature and low pH associated with muscle fatigue or damage. The purpose of this study was to evaluate the individual effects of physiologically relevant hyperthermia and acidosis on equine skeletal muscle mitochondrial function, using ex vivo measurement of oxygen consumption to assess the function of different mitochondrial elements. Fresh triceps muscle biopsies from 6 healthy unfit Thoroughbred geldings were permeabilised to permit diffusion of small molecular weight substrates through the sarcolemma and analysed in a high resolution respirometer at 38, 40, 42, and 44 °C, and pH=7.1, 6.5, and 6.1. Oxygen consumption was measured under conditions of non-phosphorylating (leak) respiration and phosphorylating respiration through Complex I and Complex II. Data were analysed using a one-way repeated measures ANOVA and data are expressed as mean ± standard deviation. Leak respiration was ~3-fold higher at 44 °C compared to 38 °C regardless of electron source (Complex I: 22.88±3.05 vs 8.08±1.92 pmol O2/mg/s), P=0.002; Complex II: 79.14±23.72 vs 21.43±11.08 pmol O2/mg/s, P=0.022), resulting in a decrease in efficiency of oxidative phosphorylation. Acidosis had minimal effect on mitochondrial respiration at pH=6.5, but pH=6.1 resulted in a 50% decrease in mitochondrial oxygen consumption. These results suggest that skeletal muscle hyperthermia decreases the efficiency of oxidative phosphorylation through increased leak respiration, thus providing a specific biochemical basis for hyperthermia-induced muscle fatigue. The effect of myocellular acidosis on mitochondrial respiration was minimal under typical levels of acidosis, but atypically severe acidosis can lead to impairment of mitochondrial function.

Primary causes of decreased mitochondrial oxygen consumption during metabolic depression in snail cells

2002 ◽  
Vol 282 (2) ◽  
pp. R372-R382 ◽  
Author(s):  
Tammie Bishop ◽  
Julie St-Pierre ◽  
Martin D. Brand
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Respiration ◽  
Mitochondrial Membrane ◽  
Substrate Oxidation ◽  
Proton Leak ◽  
Mitochondrial Oxygen Consumption ◽  
Atp Turnover ◽  
Hypometabolic State ◽  
Kinetics Of

Cells isolated from the hepatopancreas of estivating snails ( Helix aspersa) have strongly depressed mitochondrial respiration compared with controls. Mitochondrial respiration was divided into substrate oxidation (which produces the mitochondrial membrane potential) and ATP turnover and proton leak (which consume it). The activity of substrate oxidation (and probably ATP turnover) decreased, whereas the activity of proton leak remained constant in estivation. These primary changes resulted in a lower mitochondrial membrane potential in hepatopancreas cells from estivating compared with active snails, leading to secondary decreases in respiration to drive ATP turnover and proton leak. The respiration to drive ATP turnover and proton leak decreased in proportion to the overall decrease in mitochondrial respiration, so that the amount of ATP turned over per O2 consumed remained relatively constant and aerobic efficiency was maintained in this hypometabolic state. At least 75% of the total response of mitochondrial respiration to estivation was caused by primary changes in the kinetics of substrate oxidation, with only 25% or less of the response occurring through primary effects on ATP turnover.

Polarographic determination of mitochondrial respiration in Gastrothylax crumenifer

1987 ◽  
Vol 61 (2) ◽  
pp. 143-145
Author(s):  
Jawed Siddiqui ◽  
Ather H Siddiqi
Keyword(s):  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Oxidative Metabolism ◽  
Mitochondrial Respiration ◽  
Mitochondrial Atpase ◽  
Mitochondrial Oxygen Consumption ◽  
Salicylhydroxamic Acid ◽  
Gastrothylax Crumenifer ◽  
Mitochondrial Fractions

ABSTRACTThe oxidative metabolism of Gastrothylax crumenifer mitochondrial fractions was assayed polarographically at 30°C in the presence of various substrates. Succinate was most readily oxidized, malate and pyruvate were oxidized at subsantially lower retes. The spcific inhibitors such as malonate, KCN, NaN3, oxaloacetate, salicylhydroxamic acid and oligomycin effectively affected the mitochondrial oxygen consumption. The results indicate the presence of oxidative phosphorylation and cytochrome systems. Mitochondrial ATPase was found to be active.

scholarly journals The Role of Dietary Saturated Fat in Associations between Exposure to Ambient Fine Particulate Matter and Mitochondrial Respiratory Functions in Circulating Platelets

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 523-523
Author(s):  
Wan Shen ◽  
Hao Chen ◽  
James Samet ◽  
Haiyan Tong
Keyword(s):  
Oxygen Consumption ◽  
Mitochondrial Respiration ◽  
Saturated Fatty Acids ◽  
Fine Particulate Matter ◽  
Saturated Fat ◽  
Basal Respiration ◽  
Mitochondrial Oxygen Consumption ◽  
Atp Production ◽  
Consumption Rates ◽  
Mitochondrial Respiratory

Abstract Objectives Exposure to ambient fine particulate matter (PM2.5) is associated with platelet activation and increased mitochondrial respiration. The impact of dietary saturated fat on the circulating platelets is not understood. This project aimed to determine whether dietary saturated fatty acids moderate mitochondrial respiratory function in circulating platelets after short-term exposure to PM2.5. Methods Platelets were isolated from 22 healthy male volunteers (mean age ± SD, 37 ± 8.2) in a panel study and measured for mitochondrial oxygen consumption rates using an extracellular flux analyzer. Intakes of saturated fat were determined from 24 hr dietary recalls the day before the assay. Daily ambient PM2.5 concentrations during the study period were obtained from ambient air quality monitoring stations. Data were fitted with a moderation model, where the level of ambient PM2.5 was the independent variable, saturated fat intake was the moderator, and mitochondrial respiratory functions in circulating platelets were the dependent variables. Results After controlling for age, dietary consumption of saturated fat moderated the mitochondrial oxygen consumption rates of non-mitochondrial respiration, basal respiration, maximum respiration, ATP production, and spare respiratory capacity after exposure to ambient PM2.5 with 2 days lag. Specifically, the negative associations between the above mentioned mitochondrial respiratory measurements and PM2.5 levels reached statistical significance (95% Confident Intervals did not include 0) in subjects with a high intake of total saturated fat. Further, results for individual saturated fatty acid showed similar patterns, specifically that negative association between mitochondrial oxygen consumption rates of non-mitochondrial respiration, basal respiration and ATP production and levels of exposed PM2.5 was moderated by intakes of short-chain (C4:0), medium-chain (C6:0, C8:0, C10:0, C12:0), long-chain (C14:0, C16:0) saturated fatty acids. Conclusions Taken together, these preliminary findings suggest that consumption of saturated fat moderates platelet mitochondrial respiration after exposure to PM2.5.  THIS ABSTRACT OF A PROPOSED PRESENTATION DOES NOT NECESSARILY REFLECT EPA POLICY. Funding Sources This project was supported by the U.S. EPA Intramural Research Program.

scholarly journals Cell-Permeable Succinate Rescues Mitochondrial Respiration in Cellular Models of Statin Toxicity

2021 ◽  
Vol 22 (1) ◽  
pp. 424
Author(s):  
Vlad F. Avram ◽  
Imen Chamkha ◽  
Eleonor Åsander-Frostner ◽  
Johannes K. Ehinger ◽  
Romulus Z. Timar ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Respiration ◽  
Complex I ◽  
Ex Vivo ◽  
Coupling Efficiency ◽  
Human Platelets ◽  
Lipid Lowering ◽  
Lipid Lowering Therapy ◽  
Cellular Models

Statins are the cornerstone of lipid-lowering therapy. Although generally well tolerated, statin-associated muscle symptoms (SAMS) represent the main reason for treatment discontinuation. Mitochondrial dysfunction of complex I has been implicated in the pathophysiology of SAMS. The present study proposed to assess the concentration-dependent ex vivo effects of three statins on mitochondrial respiration in viable human platelets and to investigate whether a cell-permeable prodrug of succinate (complex II substrate) can compensate for statin-induced mitochondrial dysfunction. Mitochondrial respiration was assessed by high-resolution respirometry in human platelets, acutely exposed to statins in the presence/absence of the prodrug NV118. Statins concentration-dependently inhibited mitochondrial respiration in both intact and permeabilized cells. Further, statins caused an increase in non-ATP generating oxygen consumption (uncoupling), severely limiting the OXPHOS coupling efficiency, a measure of the ATP generating capacity. Cerivastatin (commercially withdrawn due to muscle toxicity) displayed a similar inhibitory capacity compared with the widely prescribed and tolerable atorvastatin, but did not elicit direct complex I inhibition. NV118 increased succinate-supported mitochondrial oxygen consumption in atorvastatin/cerivastatin-exposed platelets leading to normalization of coupled (ATP generating) respiration. The results acquired in isolated human platelets were validated in a limited set of experiments using atorvastatin in HepG2 cells, reinforcing the generalizability of the findings.

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