scholarly journals Cardiac, skeletal, and smooth muscle mitochondrial respiration: are all mitochondria created equal?

2014 ◽  
Vol 307 (3) ◽  
pp. H346-H352 ◽  
Author(s):  
Song-Young Park ◽  
Jayson R. Gifford ◽  
Robert H. I. Andtbacka ◽  
Joel D. Trinity ◽  
John R. Hyngstrom ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Respiration ◽  
Complex I ◽  
Citrate Synthase ◽  
Smooth Muscles ◽  
Respiratory Control ◽  
Respiratory Control Ratio ◽  
Mitochondrial Content ◽  
Healthy Human

Unlike cardiac and skeletal muscle, little is known about vascular smooth muscle mitochondrial respiration. Therefore, the present study examined mitochondrial respiratory rates in smooth muscle of healthy human feed arteries and compared with that of healthy cardiac and skeletal muscles. Cardiac, skeletal, and smooth muscles were harvested from a total of 22 subjects (53 ± 6 yr), and mitochondrial respiration was assessed in permeabilized fibers. Complex I + II, state 3 respiration, an index of oxidative phosphorylation capacity, fell progressively from cardiac to skeletal to smooth muscles (54 ± 1, 39 ± 4, and 15 ± 1 pmol·s−1·mg−1, P < 0.05, respectively). Citrate synthase (CS) activity, an index of mitochondrial density, also fell progressively from cardiac to skeletal to smooth muscles (222 ± 13, 115 ± 2, and 48 ± 2 μmol·g−1·min−1, P < 0.05, respectively). Thus, when respiration rates were normalized by CS (respiration per mitochondrial content), oxidative phosphorylation capacity was no longer different between the three muscle types. Interestingly, complex I state 2 normalized for CS activity, an index of nonphosphorylating respiration per mitochondrial content, increased progressively from cardiac to skeletal to smooth muscles, such that the respiratory control ratio, state 3/state 2 respiration, fell progressively from cardiac to skeletal to smooth muscles (5.3 ± 0.7, 3.2 ± 0.4, and 1.6 ± 0.3 pmol·s−1·mg−1, P < 0.05, respectively). Thus, although oxidative phosphorylation capacity per mitochondrial content in cardiac, skeletal, and smooth muscles suggest all mitochondria are created equal, the contrasting respiratory control ratio and nonphosphorylating respiration highlight the existence of intrinsic functional differences between these muscle mitochondria. This likely influences the efficiency of oxidative phosphorylation and could potentially alter ROS production.

scholarly journals Senescence-associated changes in respiration and oxidative phosphorylation in primary human fibroblasts

2004 ◽  
Vol 380 (3) ◽  
pp. 919-928 ◽  
Author(s):  
Eveline HUTTER ◽  
Kathrin RENNER ◽  
Gerald PFISTER ◽  
Petra STÖCKL ◽  
Pidder JANSEN-DÜRR ◽  
...  
Keyword(s):  
Electron Transport ◽  
Oxidative Phosphorylation ◽  
Replicative Senescence ◽  
Citrate Synthase ◽  
Human Fibroblasts ◽  
Respiratory Control ◽  
Compensatory Mechanisms ◽  
Intact Cells ◽  
Atp Production ◽  
Human Diploid Fibroblasts

Limitation of lifespan in replicative senescence is related to oxidative stress, which is probably both the cause and consequence of impaired mitochondrial respiratory function. The respiration of senescent human diploid fibroblasts was analysed by highresolution respirometry. To rule out cell-cycle effects, proliferating and growth-arrested young fibroblasts were used as controls. Uncoupled respiration, as normalized to citrate synthase activity, remained unchanged, reflecting a constant capacity of the respiratory chain. Oligomycin-inhibited respiration, however, was significantly increased in mitochondria of senescent cells, indicating a lower coupling of electron transport with phosphorylation. In contrast, growth-arrested young fibroblasts exhibited a higher coupling state compared with proliferating controls. In intact cells, partial uncoupling may lead to either decreased oxidative ATP production or a compensatory increase in routine respiration. To distinguish between these alternatives, we subtracted oligomycin-inhibited respiration from routine respiration, which allowed us to determine the part of respiratory activity coupled with ATP production. Despite substantial differences in the respiratory control ratio, ranging from 4 to 11 in the different experimental groups, a fixed proportion of respiratory capacity was maintained for coupled oxidative phosphorylation in all the experimental groups. This finding indicates that the senescent cells fully compensate for increased proton leakage by enhanced electron-transport activity in the routine state. These results provide a new insight into age-associated defects in mitochondrial function and compensatory mechanisms in intact cells.

Physiological diversity of mitochondrial oxidative phosphorylation

2006 ◽  
Vol 291 (6) ◽  
pp. C1172-C1182 ◽  
Author(s):  
G. Benard ◽  
B. Faustin ◽  
E. Passerieux ◽  
A. Galinier ◽  
C. Rocher ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Respiratory Chain ◽  
Citrate Synthase ◽  
Intrinsic Activity ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Respiratory Chain Complexes ◽  
Mitochondrial Content ◽  
Physiological Diversity ◽  
Chain Complexes ◽  
Functional Features

To investigate the physiological diversity in the regulation and control of mitochondrial oxidative phosphorylation, we determined the composition and functional features of the respiratory chain in muscle, heart, liver, kidney, and brain. First, we observed important variations in mitochondrial content and infrastructure via electron micrographs of the different tissue sections. Analyses of respiratory chain enzyme content by Western blot also showed large differences between tissues, in good correlation with the expression level of mitochondrial transcription factor A and the activity of citrate synthase. On the isolated mitochondria, we observed a conserved molar ratio between the respiratory chain complexes and a variable stoichiometry for coenzyme Q and cytochrome c, with typical values of [1–1.5]:[30–135]:[3]:[9–35]:[6.5–7.5] for complex II:coenzyme Q:complex III:cytochrome c:complex IV in the different tissues. The functional analysis revealed important differences in maximal velocities of respiratory chain complexes, with higher values in heart. However, calculation of the catalytic constants showed that brain contained the more active enzyme complexes. Hence, our study demonstrates that, in tissues, oxidative phosphorylation capacity is highly variable and diverse, as determined by different combinations of 1) the mitochondrial content, 2) the amount of respiratory chain complexes, and 3) their intrinsic activity. In all tissues, there was a large excess of enzyme capacity and intermediate substrate concentration, compared with what is required for state 3 respiration. To conclude, we submitted our data to a principal component analysis that revealed three groups of tissues: muscle and heart, brain, and liver and kidney.

Role of oxidative stress in alterations of mitochondrial function in ischemic-reperfused hearts

2007 ◽  
Vol 292 (4) ◽  
pp. H1986-H1994 ◽  
Author(s):  
Zhanna Makazan ◽  
Harjot K. Saini ◽  
Naranjan S. Dhalla
Keyword(s):  
Oxidative Stress ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Function ◽  
Mitochondrial Respiration ◽  
Diastolic Pressure ◽  
Ischemia Reperfusion ◽  
Respiratory Control ◽  
Left Ventricular ◽  
Cardiac Performance ◽  
Developed Pressure

To study the mechanisms of mitochondrial dysfunction due to ischemia-reperfusion (I/R) injury, rat hearts were subjected to 20 or 30 min of global ischemia followed by 30 min of reperfusion. After recording both left ventricular developed pressure (LVDP) and end-diastolic pressure (LVEDP) to monitor the status of cardiac performance, mitochondria from these hearts were isolated to determine respiratory and oxidative phosphorylation activities. Although hearts subjected to 20 min of ischemia failed to generate LVDP and showed a marked increase in LVEDP, no changes in mitochondrial respiration and phosphorylation were observed. Reperfusion of 20-min ischemic hearts depressed mitochondrial function significantly but recovered LVDP completely and lowered the elevated LVEDP. On the other hand, depressed LVDP and elevated LVEDP in 30-min ischemic hearts were associated with depressions in both mitochondrial respiration and oxidative phosphorylation. Reperfusion of 30-min ischemic hearts elevated LVEDP, attenuated LVDP, and decreased mitochondrial state 3 and uncoupled respiration, respiratory control index, ADP-to-O ratio, as well as oxidative phosphorylation rate. Alterations of cardiac performance and mitochondrial function in I/R hearts were attenuated or prevented by pretreatment with oxyradical scavenging mixture (superoxide dismutase and catalase) or antioxidants [ N-acetyl-l-cysteine or N-(2-mercaptopropionyl)-glycine]. Furthermore, alterations in cardiac performance and mitochondrial function due to I/R were simulated by an oxyradical-generating system (xanthine plus xanthine oxidase) and an oxidant (H2O2) either upon perfusing the heart or upon incubation with mitochondria. These results support the view that oxidative stress plays an important role in inducing changes in cardiac performance and mitochondrial function due to I/R.

scholarly journals The effect of sulodexide on placental mitochondria function in rats with experimental preeclampsia

2016 ◽  
Vol 62 (5) ◽  
pp. 572-576 ◽  
Author(s):  
T.A. Popova ◽  
V.N. Perfilova ◽  
G.A. Zhakupova ◽  
V.E. Verovsky ◽  
O.V. Ostrovskij ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Mitochondrial Dysfunction ◽  
Respiratory Control ◽  
Negative Control ◽  
Urinary Protein ◽  
Control Group ◽  
Respiratory Control Ratio ◽  
Pregnant Rats ◽  
Pronounced Increase ◽  
Uncoupling Of Oxidative Phosphorylation

Substitution of drinking water for 1.8% NaCl in pregnant rats caused a pronounced increase in arterial pressure by 24,3% and urinary protein by 117% to day 21 of pregnancy. State 4 respiration of isolated placental mitochondria in the group of negative control was 3- and 1.5-fold higher with malate/glutamate and succinate as substrates than in placental mitochondria isolated from uncomplicated pregnant animals. This led to a decrease of the respiratory control ratio. These results suggest that development of experimental preeclampsia is accompanied by mitochondrial dysfunction through uncoupling of oxidative phosphorylation. Daily administration of sulodexide to females with experimental preeclampsia (EP) per os at a dose of 30 LE during the whole period of gestation decreased manifestations of the disease as evidenced by a slight increase in blood pressure (by 8,6%) and less pronounces increase in urinary protein (by 58,9%). Sulodexide decreased development of mitochondrial dysfunction in EP rats as shown a decrease of non-stimulated ADP respiration with malate/glutamate and succinate (4.5- and 2.5-fold, respectively) as compared with the negative control group and the corresponding increase in the respiratory control ratio (2.5- and 1.5-fold, respectively). Thus, sulodexide reduces uncoupling of oxidative phosphorylation and enhances the functional activity of mitochondria in EP animals, possibly due to its antioxidant and endotelioprotective effects.

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.

Effects of 6-hydroxydopamine on oxidative phosphorylation of mitochondria from rat striatum, cortex, and liver

1988 ◽  
Vol 66 (3) ◽  
pp. 376-379 ◽  
Author(s):  
J. H. Thakar ◽  
M. N. Hassan
Keyword(s):  
Oxidative Phosphorylation ◽  
Incubation Medium ◽  
Respiratory Control ◽  
Rat Striatum ◽  
Respiratory Control Ratio ◽  
Chemical Sympathectomy ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Consumption Ratio ◽  
6 Hydroxydopamine

The catecholamine neurotoxin 6-hydroxydopamine (6-OHDA) has been used to produce cardiac chemical sympathectomy as well as a model of parkinsonism. Several mechanisms have been proposed to explain its cytotoxicity, including the productions of quinones, hydrogen peroxide, and free radicals by autooxidation and the uncoupling of mitochondrial oxidative phosphorylation. We have observed that 6-OHDA at a concentration of 0.05 mM rapidly consumes oxygen from the mitochondrial incubation medium but does not affect oxidative phosphorylation in the mitochondria from rat striatum, cortex, and liver. At the higher concentration of 0.5 mM, 6-OHDA consumes all of the available oxygen from the incubation medium. Mitochondria exposed to this concentration of 6-OHDA show decreases in the respiratory control ratio and adenosine triphosphate synthesis as measured by the consumption ratio of ADP to oxygen. Thus, only the higher (0.5 mM) concentration of 6-OHDA, which produces anoxia in vitro, also causes mitochondrial damage.

scholarly journals Mitochondrial respiration and H2O2 emission in saponin-permeabilized murine diaphragm fibers: optimization of fiber separation and comparison to limb muscle

2019 ◽  
Vol 317 (4) ◽  
pp. C665-C673
Author(s):  
Dongwoo Hahn ◽  
Ravi A. Kumar ◽  
Terence E. Ryan ◽  
Leonardo F. Ferreira
Keyword(s):  
Mitochondrial Respiration ◽  
Citrate Synthase ◽  
Limb Muscle ◽  
Mitochondrial Content ◽  
New Approach ◽  
Disease States ◽  
Fiber Separation ◽  
Mouse Diaphragm ◽  
Permeabilized Fibers ◽  
Permeabilized Muscle

Diaphragm abnormalities in aging or chronic diseases include impaired mitochondrial respiration and H2O2 emission, which can be measured using saponin-permeabilized muscle fibers. Mouse diaphragm presents a challenge for isolation of fibers due to relatively high abundance of connective tissue in healthy muscle that is exacerbated in disease states. We tested a new approach to process mouse diaphragm for assessment of intact mitochondria respiration and ROS emission in saponin-permeabilized fibers. We used the red gastrocnemius (RG) as “standard” limb muscle. Markers of mitochondrial content were two– to fourfold higher in diaphragm (Dia) than in RG ( P < 0.05). Maximal O2 consumption ( JO2: pmol·s−1·mg−1) in Dia was higher with glutamate, malate, and succinate (Dia 399 ± 127, RG 148 ± 60; P < 0.05) and palmitoyl-CoA + carnitine (Dia 15 ± 5, RG 7 ± 1; P < 0.05) than in RG, but not different between muscles when JO2 was normalized to citrate synthase activity. Absolute JO2 for Dia was two– to fourfold higher than reported in previous studies. Mitochondrial JH2O2 was higher in Dia than in RG ( P < 0.05), but lower in Dia than in RG when JH2O2 was normalized to citrate synthase activity. Our findings are consistent with an optimized diaphragm preparation for assessment of intact mitochondria in permeabilized fiber bundles. The data also suggest that higher mitochondrial content potentially makes the diaphragm more susceptible to “mitochondrial onset” myopathy. Overall, the new approach will facilitate testing and understanding of diaphragm mitochondrial function in mouse models that are used to advance biomedical research and human health.

Respiration and oxidative phosphorylation by muscle and heart mitochondria of hamsters with hereditary myocardiopathy and polymyopathy

1968 ◽  
Vol 46 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Klaus Wrogemann ◽  
M. C. Blanchaer
Keyword(s):  
Skeletal Muscle ◽  
Oxidative Phosphorylation ◽  
Histological Examination ◽  
Creatine Phosphokinase ◽  
Respiratory Control ◽  
Isolation Procedure ◽  
Heart Mitochondria ◽  
Respiratory Control Ratio ◽  
Skeletal Muscle Mitochondria ◽  
Serum Creatine Phosphokinase

Mitochondria isolated from skeletal muscle and heart of normal Syrian hamsters and from hamsters of the BIO 14.6 myopathic strain aged 97–124 days were studied. Histological examination of the tissues and serum creatine phosphokinase determinations established that the disease was active in the dystrophic animals. In the mitochondrial isolation procedure the minced tissue was incubated before homogenization in a mannitol–sucrose–EDTA medium containing a proteinase (Nagarse). Polarographic estimations with pyruvate–malate as substrate, in the presence and absence of ADP, indicated that the rate of O2 uptake, ADP/O ratio, and respiratory control ratio (state 3 to 4 transition) of the heart mitochondria did not suffer significantly between the normal and myopathic groups. The findings with the skeletal muscle mitochondria were similar. L-α-Glycerophosphate oxidation also was not affected by the myopathy but the rate of NADH oxidation was 35% slower in the heart mitochondria of the BIO 14.6 strain.

Pseudomonas aeruginosa lipopolysaccharide: an uncoupler of mitochondrial oxidative phosphorylation

1975 ◽  
Vol 21 (6) ◽  
pp. 877-883 ◽  
Author(s):  
G. Gordon Greer ◽  
F. H. Milazzo
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Oxygen Uptake ◽  
Oxidative Phosphorylation ◽  
Respiratory Control ◽  
Substrate Oxidation ◽  
Respiratory Control Ratio ◽  
Mitochondrial Oxidative Phosphorylation

The addition of Pseudomonas aeruginosa KCIIR LPS to respiring mitochondria stimulated the rate of substrate oxidation, reduced the respiratory control ratio, stimulated oxygen uptake in state 4, and released the inhibition imposed upon state 3 by atractyloside. It was concluded that LPS acted as an uncoupler of oxidative phosphorylation and that it produced effects similar to those observed with the classical uncoupler 2,4-dinitrophenol.

scholarly journals Improved method for isolation of coupled mitochondria of Araucaria angustifolia (Bert.) O. Kuntze

2004 ◽  
Vol 47 (6) ◽  
pp. 873-879 ◽  
Author(s):  
André Bellin Mariano ◽  
Leonardo Kovalhuk ◽  
Caroline Valente ◽  
Juliana Maurer-Menestrina ◽  
Adaucto Bellarmino Pereira-Netto ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Oxidative Phosphorylation ◽  
Embryogenic Callus ◽  
Respiratory Control ◽  
Mitochondrial Bioenergetics ◽  
Respiratory Control Ratio ◽  
Araucaria Angustifolia ◽  
Improved Method ◽  
First Time

A method for the isolation of coupled mitochondria from the callus of Araucaria angustifolia is described for the first time. Mitochondria were isolated from embryogenic callus of A. angustifolia. They were metabolically active, able to sustain oxidative phosphorylation as shown by respiratory control ratio values, which were about 2.4 when respiring on succinate as substrate. Oxygen uptake experiments, using freeze-thawed disrupted mitochondria, showed the presence of alternative rotenone-insensitive NAD(P)H dehydrogenases, which were stimulated by Ca2+. The procedure now described for the isolation of A. angustifolia mitochondria is an important new tool, allowing the investigation of mitochondrial bioenergetics and metabolism and physiology of plants.

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