Activities of cytochrome c oxidase and citrate synthase in lymphocytes of obese and normal-weight subjects

2002 ◽  
Vol 26 (8) ◽  
pp. 1110-1117 ◽  
Author(s):  
M Čapková ◽  
J Houštěk ◽  
H Hansíková ◽  
V Hainer ◽  
M Kunešová ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Citrate Synthase ◽  
Normal Weight

Mitochondrial DNA replication and transcription are dissociated during embryonic cardiac hypertrophy

1991 ◽  
Vol 261 (6) ◽  
pp. C1091-C1098 ◽  
Author(s):  
J. M. Kennedy ◽  
S. R. Lobacz ◽  
S. W. Kelley
Keyword(s):  
Mitochondrial Dna ◽  
Cytochrome C ◽  
Cardiac Hypertrophy ◽  
Cytochrome C Oxidase ◽  
Oxidase Activity ◽  
Citrate Synthase ◽  
Incubation Temperature ◽  
Mitochondrial Gene ◽  
Gene Replication ◽  
Mitochondrial Dna Copy Number

Cardiac hypertrophy was produced in embryonic chicks by decreasing the incubation temperature from 38 degrees C to 32 degrees C on day 11. Increases in ventricular protein, RNA, and DNA support the cardiac enlargement. Cytochrome-c oxidase activity and citrate synthase activity were depressed in hypothermic ventricles by 63% and 56%, respectively. No significant differences were seen in enzyme activities in pectoralis muscles. The involvement of mitochondrial gene replication and transcription was evaluated using a cDNA clone for the mitochondrially encoded subunit III of cytochrome-c oxidase (CO III). Quantitative slot-blot analysis demonstrated that the relative CO III mRNA concentration was reduced in hypothermic ventricles. In contrast, the relative mitochondrial DNA concentration was increased in hypothermic ventricles. Taken together, these data indicate that a hypothermia-induced decrease in cytochrome-c oxidase activity is associated with a decrease in CO III mRNA, which is not coupled to a decrease in the mitochondrial DNA copy number. This dissociation of mitochondrial gene replication and transcription may provide a useful model for examining the regulation of mitochondrial biogenesis.

Mitochondrial Protein Content and in Vivo Synthesis Rates in Skeletal Muscle from Critically Ill Rats

1996 ◽  
Vol 91 (4) ◽  
pp. 475-481 ◽  
Author(s):  
Olav E. Rooyackers ◽  
Alexande R H. Kersten ◽  
Anton J. M. Wagenmakers
Keyword(s):  
Skeletal Muscle ◽  
Critical Illness ◽  
Cytochrome C ◽  
Protein Content ◽  
Cytochrome C Oxidase ◽  
Citrate Synthase ◽  
Mitochondrial Protein ◽  
Substantial Reduction ◽  
Mitochondrial Content

1. Recently we reported decreased activities of two mitochondrial marker enzymes (citrate synthase and cytochrome c oxidase) in skeletal muscle from a rat model of critical illness (zymosan injection). In the present study we investigated (i) whether these decreases in enzyme activity reflect a reduction in mitochondrial content and (ii) whether this potential reduction in mitochondrial content was the result of decreased mitochondrial protein synthesis rates. 2. Mitochondrial protein content was calculated from the activities of cytochrome c oxidase in whole-muscle homogenates and purified mitochondria. Synthesis rates of mitochondrial protein in vivo were studied by measuring the incorporation of [3H]phenylalanine into mitochondrial protein using the flooding dose technique. 3. Mitochondrial protein content was reduced to 54% of that measured in the pair-fed rats and to 71% of that measured in control rats fed ad libitum 2 days after the zymosan treatment The decreased mitochondrial protein content observed 2 days after zymosan challenge was preceded by a reduced rate of synthesis of mitochondrial protein 16 h after treatment. Both changes were of greater magnitude than the general muscle wasting and the decreased rate of synthesis of mixed protein observed in the zymosan-treated rats. 4. We conclude that the acute phase of critical illness in zymosan-treated rats is characterized by a substantial reduction in muscle mitochondria that is at least in part caused by a decreased rate of synthesis of mitochondrial protein. This derangement in mitochondrial protein metabolism may be related to the impaired muscle function observed during and after critical illness.

Activity-induced adaptations in skeletal muscles of iron-deficient rabbits

1988 ◽  
Vol 65 (2) ◽  
pp. 782-787 ◽  
Author(s):  
W. R. Harlan ◽  
R. S. Williams
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Skeletal Muscles ◽  
Citrate Synthase ◽  
Contractile Activity ◽  
Motor Nerve ◽  
Anterior Compartment ◽  
Iron Deficient ◽  
Electrical Pacing ◽  
Aldolase A

The purpose of this study was to determine whether severe iron deficiency alters the adaptive response of skeletal muscle fibers to a sustained increase in tonic contractile activity. Seven weanling rabbits consumed a low iron diet and underwent phlebotomy twice weekly for 6 mo, resulting in severe anemia (mean Hb 5.5 g/dl). Compared with control animals, tibialis anterior skeletal muscles of iron-deficient animals exhibited reduced concentrations of cytochrome c (4.4 +/- 0.7 vs. 8.6 +/- 0.7 nmol/g tissue; P less than 0.01), and reduced activities of citrate synthase (83 +/- 10 vs. 133 +/- 13 mU/mg protein; P less than 0.01) and cytochrome-c oxidase (2.2 +/- 0.2 vs. 3.6 +/- 0.5 U/mg protein; P less than 0.05). In these muscles mitochondria were swollen and displayed deformed cristae. Less severe biochemical abnormalities were observed in cardiac and soleus skeletal muscles. Ten days of continuous electrical stimulation of the motor nerve supplying anterior compartment muscles of iron-deficient rabbits increased expression of mitochondrial proteins: cytochrome c was increased to 154% of control levels (P less than 0.05), and cytochrome-c oxidase and citrate synthase activities were increased to 199 and 272% of control levels, respectively (P less than 0.005). In addition, electrical pacing increased the fractional volume of mitochondria observed by electron microscopy and reduced the activity of aldolase A by 28% (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Human skeletal muscle adaptation in response to chronic low-frequency electrical stimulation

1994 ◽  
Vol 77 (4) ◽  
pp. 1885-1889 ◽  
Author(s):  
R. Theriault ◽  
G. Theriault ◽  
J. A. Simoneau
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Human Skeletal Muscle ◽  
Citrate Synthase ◽  
Low Frequency ◽  
Vastus Lateralis Muscle ◽  
Activity Levels ◽  
Hydroxyacyl Coa Dehydrogenase

The purpose of the study was to verify the influence of several weeks of chronic low-frequency electrical stimulation (LFES) on the metabolic profile and functional capacity of human skeletal muscle. Knee extensor muscles (KEM) of eight subjects were electrically stimulated at 8 Hz for 8 h/day and 6 days/wk. Vastus lateralis muscle samples were taken before, after 4 wk, and after 8 wk of LFES, and activities of anaerobic (creatine kinase, phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase) and aerobic-oxidative (citrate synthase, 3-hydroxyacyl-CoA dehydrogenase, cytochrome-c oxidase) enzyme markers were determined. KEM dynamic performance was also assessed before, after 4 wk, and after 8 wk of LFES. Activity levels of anaerobic enzymes were not altered, whereas the activity levels of citrate synthase (29%),3-hydroxyacyl-CoA dehydrogenase (22%), and cytochrome-c oxidase (25%) were significantly increased after 4 wk of LFES but were not further increased after 4 additional wk of LFES. KEM performance was also improved (P < 0.05) but leveled off after 4 wk of LFES. Although significant changes were observed, the results of the present study suggest that the muscle characteristics investigated in the current study have a limited capacity of adaptation in response to this form of chronic LFES.

Maximal enzyme activities of energy production pathways in the heart, hepatopancreas, and white muscle of the giant scallop (Placopecten magellanicus) and lobster (Homarus americanus)

1992 ◽  
Vol 70 (4) ◽  
pp. 720-724 ◽  
Author(s):  
John M. Stewart ◽  
Molly E. Brass ◽  
Robert C. Carlin ◽  
Heather Black
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
White Muscle ◽  
Citrate Synthase ◽  
Ketone Bodies ◽  
Homarus Americanus ◽  
Carnitine Palmitoyltransferase ◽  
Placopecten Magellanicus ◽  
Flexor Muscle ◽  
Low Levels

The maximal activities of enzymes in energy pathways were measured in the ventricle, hepatopancreas, and white muscle of lobster (Homarus americanus; abdominal flexor) and giant scallop (Placopecten magellanicus; phasic adductor). Both animals show an energy metabolism based upon the utilization of carbohydrate. Carnitine palmitoyltransferase activity was not detected, and this was interpreted as an incapacity for mitochondrial β-oxidation of fatty acids; the absence of 3-hydroxybutyrate dehydrogenase and D-3-hydroxybutyrate indicated that ketone bodies were not a significant energy source. The levels of hexokinase, phosphofructokinase I, citrate synthase, and cytochrome c oxidase in the myocardia of both animals suggest a dependence on the aerobic processing of both blood-borne and glycogen-derived glucose. The significance of the enzyme activity data in the hepatopancreas of both animals was not immediately apparent. The abdominal flexor muscle of the lobster and the phasic adductor of the scallop showed enzyme profiles that suggest a reliance on glycolysis to fuel rapid bursts of activity. In the lobster flexor the presence of hexokinase and phosphofructokinase I along with low levels of citrate synthase and cytochrome c oxidase indicated that this tissue can utilize blood-borne and glycogenic glucose anaerobically. The absence of hexokinase, the low levels of citrate synthase and cytochrome c oxidase, and the presence of phosphofructokinase I in the scallop adductor suggested a reliance upon glycogen-fueled glycolysis to power burst activity. 3-Hydroxyacyl-CoA dehydrogenase was found in all tissues except the lobster flexor, which was curious in light of the undetectable activity of carnitine palmitoyltransferase.

Effect of thyroid status on the expression of metabolic enzymes during chronic stimulation

1992 ◽  
Vol 263 (4) ◽  
pp. C788-C793 ◽  
Author(s):  
D. A. Hood ◽  
J. A. Simoneau ◽  
A. M. Kelly ◽  
D. Pette
Keyword(s):  
Enzyme Activity ◽  
Thyroid Hormone ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Tibialis Anterior ◽  
Citrate Synthase ◽  
Tibialis Anterior Muscle ◽  
Mitochondrial Genes ◽  
Thyroid Status ◽  
Chronic Stimulation

The effect of thyroid status on the expression of cytochrome c oxidase (CYTOX) and the activities of citrate synthase (CS) and phosphofructokinase (PFK) were examined in chronically stimulated (10 Hz; 35 days) and contralateral, nonstimulated rat tibialis anterior muscle of hypothyroid, hyperthyroid, and euthyroid animals. Stimulation increased CYTOX activity by 2.7-, 3.2-, and 4.9-fold in hyperthyroid, euthyroid, and hypothyroid animals, respectively, to similar absolute values. CS displayed similar increases. Stimulation reduced PFK activity in hypothyroid and euthyroid animals to 45% and 60% of control values. This effect was abolished with hyperthyroidism. Thus stimulation and thyroid hormone act antagonistically on PFK activity. Stimulation increased CYTOX subunit III (mitochondrially encoded) mRNA by 2.5- and 2.9-fold in hyperthyroid and euthyroid animals. Similar increases were observed in the nuclear-encoded mRNAs of CYTOX subunit VIc in euthyroid muscle. In hyperthyroid and euthyroid conditions, the mRNA changes paralleled the increases in enzyme activity. In hypothyroid muscle, the increase in mRNA was less for subunit VIc than III, suggesting that hypothyroidism upsets the coordinate expression of nuclear and mitochondrial genes. Further, the increases in CYTOX activity exceeded that of both subunit mRNAs in hypothyroid muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals High-altitude ancestry and hypoxia acclimation have distinct effects on exercise capacity and muscle phenotype in deer mice

2015 ◽  
Vol 308 (9) ◽  
pp. R779-R791 ◽  
Author(s):  
Mikaela A. Lui ◽  
Sajeni Mahalingam ◽  
Paras Patel ◽  
Alex D. Connaty ◽  
Catherine M. Ivy ◽  
...  
Keyword(s):  
Cytochrome C ◽  
High Altitude ◽  
Cytochrome C Oxidase ◽  
Exercise Performance ◽  
Citrate Synthase ◽  
Oxidative Enzymes ◽  
Deer Mice ◽  
Lung Mass ◽  
Lactate Dehydrogenase Activity ◽  
Hypoxia Acclimation

The hypoxic and cold environment at high altitudes requires that small mammals sustain high rates of O2 transport for exercise and thermogenesis while facing a diminished O2 availability. We used laboratory-born and -raised deer mice ( Peromyscus maniculatus) from highland and lowland populations to determine the interactive effects of ancestry and hypoxia acclimation on exercise performance. Maximal O2 consumption (V̇o2max) during exercise in hypoxia increased after hypoxia acclimation (equivalent to the hypoxia at ∼4,300 m elevation for 6–8 wk) and was consistently greater in highlanders than in lowlanders. V̇o2max during exercise in normoxia was not affected by ancestry or acclimation. Highlanders also had consistently greater capillarity, oxidative fiber density, and maximal activities of oxidative enzymes (cytochrome c oxidase and citrate synthase) in the gastrocnemius muscle, lower lactate dehydrogenase activity in the gastrocnemius, and greater cytochrome c oxidase activity in the diaphragm. Hypoxia acclimation did not affect any of these muscle traits. The unique gastrocnemius phenotype of highlanders was associated with higher mRNA and protein abundances of peroxisome proliferator-activated receptor γ (PPARγ). Vascular endothelial growth factor (VEGFA) transcript abundance was lower in highlanders, and hypoxia acclimation reduced the expression of numerous genes that regulate angiogenesis and energy metabolism, in contrast to the observed population differences in muscle phenotype. Lowlanders exhibited greater increases in blood hemoglobin content, hematocrit, and wet lung mass (but not dry lung mass) than highlanders after hypoxia acclimation. Genotypic adaptation to high altitude, therefore, improves exercise performance in hypoxia by mechanisms that are at least partially distinct from those underlying hypoxia acclimation.

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