The effects of ischemia and experimental conditions on the respiration rate of cardiac fibers

Toleikis, Adolfas; Majienė, Daiva; Trumbeckaitė, Sonata; Dagys, Arvydas

doi:10.1007/978-1-4615-6111-8_13

Cited by 5 publications

(5 citation statements)

References 7 publications

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“…It was negligible or absent with the latter substrate. The effects of cytochrome c and their difference between substrates largely increased in the case of ischemia (1 hr), which is known to produce the injury to OMM (Kay et al, 1997a, b;Toleikis et al, 1997).…”

Section: Resultsmentioning

confidence: 97%

“…Bundles of the heart muscle fibers, approximately 0.2-0.3 mm in diameter, were prepared as described in Ref (Toleikis et al, , 1997(Toleikis et al, , 2001. Bundles of fibers were transferred to cooled solution A containing 20 mM imidazole, 20 mM taurine, 0.5 mM dithiothreitol, 7.1 mM MgCl 2 , 50 mM 2-[N-Morpholino]ethanesulfonic acid (MES), 5 mM ATP, 15 mM phosphocreatine, 2.6 mM CaK 2 EGTA and 7.4 mM K 2 EGTA (free Ca 2+ concentration 0.1 lM) (pH 7.0 adjusted with KOH at 2°C), supplemented with 50 lg/ml saponin (from Gypsophila; sapogenin content 17%; Sigma) alone or in combination with 3 mg/ml collagenase (Type IV, Sigma) and incubated for 30 min.…”

Section: Methodsmentioning

confidence: 99%

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Cytochrome c Effect on Respiration of Heart Mitochondria: Influence of Various Factors

2005

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The effect of exogenous cytochrome c on respiration rate of the rat and human heart mitochondria was assessed in situ, using permeabilized fibers. It was (i) much more pronounced in State 2 and 4 than in State 3 with all the respiratory substrates (pyruvate+malate, succinate, palmitoyl-CoA+carnitine and octanoyl-L-carnitine), (ii) different with different substrates, (iii) much higher after ischemia in both metabolic states, particularly in the case of succinate oxidation compared to pyruvate+malate, (iv) the highest in State 4 with succinate as a substrate. Similar results were obtained with the isolated rat and rabbit heart mitochondria. The differences in the degree of stimulation of mitochondrial respiration by cytochrome c and, thus, sensitivity of cytochrome c test in evaluation of the intactness/injury of outer mitochondrial membrane are probably determined by the differences in the cytochrome c role in the control of mitochondrial respiration in the above-described conditions.

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Section: Resultsmentioning

confidence: 97%

Section: Methodsmentioning

confidence: 99%

Cytochrome c Effect on Respiration of Heart Mitochondria: Influence of Various Factors

2005

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“…Under a microscope, the muscle fibres were isolated from the muscle specimens in the isolation buffer with sharp forceps to avoid any mechanical stress. The isolated muscle fibres were incubated in the isolation buffer with 0•75 mg/ml collagenase for 30 min (19) . Afterwards, the muscle fibres were incubated in the buffer with 100 μg/ml saponin for 30 min.…”

Section: Isolation Of Muscle Fibres and Permeabilisationmentioning

confidence: 99%

Curcumin induces mitochondrial biogenesis by increasing cyclic AMP levels via phosphodiesterase 4A inhibition in skeletal muscle

et al. 2021

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Background: Previous research has suggested that curcumin potentially induces mitochondrial biogenesis in skeletal muscle via increasing cAMP levels. However, the regulatory mechanisms for this phenomenon remain unknown. The purpose of the present study was to clarify the mechanism by which curcumin activates cAMP-related signalling pathways that upregulate mitochondrial biogenesis and respiration in skeletal muscle. Methods: The effect of curcumin treatment (i.p., 100 mg/kg-BW/day for 28 days) on mitochondrial biogenesis was determined in rats. The effects of curcumin and exercise (swimming for 2 h/day for 3 days) on the cAMP signalling pathway were determined in the absence and presence of phosphodiesterase (PDE) or protein kinase A (PKA) inhibitors. Mitochondrial respiration, citrate synthase (CS) activity, cAMP content, and protein expression of cAMP/PKA signalling molecules were analysed. Results: Curcumin administration increased COX-IV protein expression, and CS and complex I activity, consistent with the induction of mitochondrial biogenesis by curcumin. Mitochondrial respiration was not altered by curcumin treatment. Curcumin and PDE inhibition tended to increase cAMP levels with or without exercise. In addition, exercise increased the phosphorylation of PDE4A, whereas curcumin treatment strongly inhibited PDE4A phosphorylation regardless of exercise. Furthermore, curcumin promoted AMPK phosphorylation and PGC-1α deacetylation. Inhibition of PKA abolished the phosphorylation of AMPK. Conclusion: The present results suggest that curcumin increases cAMP levels via inhibition of PDE4A phosphorylation, which induces mitochondrial biogenesis through a cAMP/PKA/AMPK signalling pathway. Our data also suggest the possibility that curcumin utilizes a regulatory mechanism for mitochondrial biogenesis that is distinct from the exercise-induced mechanism in skeletal muscle.

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“…The protocol below is adapted for trout from Toleikis et al (1997). The ventricle was cut in three to four pieces which were weighed (range: 10 -25 mg) and placed in 1.5 ml of ice-cold buffer (ATP: 1 mM, PCr: 2 mM, Dithiothreitol: 0.5 mM EDTA: 5.5 mM, MgCl 2 : 2.5 mM, Imidazole: 10.0 mM, HEPES: 20.0 mM, KCl: 70.0 mM; pH 7.4) during less than 10 min to eliminate all traces of blood.…”

Section: Permeabilized Ventricular Myofibers Oxygen Consumptionmentioning

confidence: 99%

Trade-off between thermal sensitivity, hypoxia tolerance and growth in fish

Roze

Christen

Amérand

et al. 2013

Journal of Thermal Biology

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International audienceOne outcome of contemporary climate trends is that the involvement of hypoxia and heat tolerance in determining individual fitness will increase in many fish populations. Large fish are believed to be more tolerant to hypoxia than small fish (Nilsson and Östlund-Nilsson, 2008) whereas thermal sensitivity is thought to decrease with body size (Clark et al., 2008). To better understand the bases of inter-individual variation in environmental adaptation performance, the current study examined hypoxia and heat tolerance in a fast growing (FGS; 288.3 ±14.4 g, 26.04±0.49 cm) and a slow growing (SGS; 119.95±6.41 g; 20.98±0.41 cm) strain of 1-year old rainbow trout (Oncorhynchus mykiss). This examination was conducted using two standardized challenge tests aimed at assessing individual incipient lethal oxygen saturation and incipient upper lethal temperature. Results to these tests were then cross-correlated with swim tests during which individual basal and active metabolic rate values were also measured. Measurements of permeabilized ventricular myofibers oxygen consumption were also conducted, as well as various organ-to-body-mass ratios. Experimental data showed that FGS was more hypoxia tolerant than SGS (13.4 to 16.7% air sat versus 14.7 to 18.9% air sat respectively). On the other hand, FGS was found less tolerant to heat than SGS (24.7-27.6 °C versus 28.5 to 29.7 °C respectively). Adding to the body size effect, another source of inter-individual variation in environmental tolerance was found. Residual analysis highlighted that whereas none of the individual morphometric and energetic traits correlated with hypoxia tolerance, permeabilized ventricular myofibers maximal oxygen consumption correlated well with individual tolerance to heat

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The effects of ischemia and experimental conditions on the respiration rate of cardiac fibers

Cited by 5 publications

References 7 publications

Cytochrome c Effect on Respiration of Heart Mitochondria: Influence of Various Factors

Cytochrome c Effect on Respiration of Heart Mitochondria: Influence of Various Factors

Curcumin induces mitochondrial biogenesis by increasing cyclic AMP levels via phosphodiesterase 4A inhibition in skeletal muscle

Trade-off between thermal sensitivity, hypoxia tolerance and growth in fish

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