Peculiarities of functioning of liver mitochondria of the river lamprey Lampetra fluviatilis and the common frog Rana temporaria at periods of suppression and activation of energy metabolism

Emelyanova, Larisa; Savina, Margarita V.; Belyaeva, E. S.; Brailovskaya, I. V.

doi:10.1134/s0022093007060047

Cited by 7 publications

(26 citation statements)

References 17 publications

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“…Secondly, the thermal condition of respiratory measures (20°C in the present study vs. 25°C or 37°C in the above‐mentioned articles) could well explain the lower mitochondrial respiration rate in our study. In this context, if we assumed a Q10 of 2.4–2.7 to estimate the rates of mitochondrial respiration at 37°C (Chamberlin, ) then our data (state 3: 15–19 nmol O/min·mg of protein) are comparable to the reported values of 25–26 nmol O/min·mg of protein (Hulbert et al., ; Emel'yanova et al., ). Finally, the magnitude of the RCR (data from Figs.…”

Section: Discussionsupporting

confidence: 84%

“…However, the reported frogs' values are similar to the ATP/O values reported in liver mitochondria from garter snakes (Robert and Bronikowski, 2010). Another concern about the present data is the apparent low protein specific respiratory rates of frog liver mitochondria compared with similar published data, i.e., liver mitochondria from amphibians' species (Hulbert et al, 2006;Emel'yanova et al, 2007). There are two main parameters that might explain the present low respiration rates.…”

Section: Discussionsupporting

confidence: 74%

“…There are two main parameters that might explain the present low respiration rates. Firstly, the time of capture in the year as it has been found that the rate of liver mitochondrial respiration can be more than twofold lower in frog caught in spring than in summer (Emel'yanova et al., ). In the present study, frogs were caught in March, suggesting that our mitochondrial parameters should be in the lower range of seasonal variation.…”

Section: Discussionmentioning

confidence: 99%

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David and Goliath: A Mitochondrial Coupling Problem?

et al. 2012

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An organism's size, known to affect biological structures and processes from cellular metabolism to population dynamics, depends upon the duration and rate of growth. However, it is still poorly understood how mitochondrial function affects the energetic basis of growth, especially in ectotherms, which represent a huge majority of animal biodiversity. Here, we present an intraspecies comparison of neighboring populations of frogs (Rana temporaria) that have large differences in body mass even at the same age. By investigating liver mitochondrial bioenergetics, we find that frogs with high growth rates and large body sizes exhibit higher ATP synthesis rates and more efficient oxidative phosphorylation compared to the smaller frogs with low growth rates. This higher energy transduction efficiency is not associated with significant increased oxidative capacity or membrane potential values, but instead may rely on a higher mitochondrial phosphorylation system activity in combination with a lower inner membrane proton leakage. Overall, the present study introduces the mitochondrial energy transduction system as an important mechanism for balancing physiological and ecological trade-offs associated with body size. Whether phenotype differences in mitochondrial function result from local ecological constraints or reflect a natural genetic variability within wild populations of common frogs remains an open question. However, our findings highlight the need for closer consideration of all aspects of mitochondrial metabolism for a better understanding of the physiological basis of the link between size, metabolism, and energy production in wild-dwelling organisms.

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Section: Discussionsupporting

confidence: 84%

Section: Discussionsupporting

confidence: 74%

Section: Discussionmentioning

confidence: 99%

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David and Goliath: A Mitochondrial Coupling Problem?

et al. 2012

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“…) and the animal species involved (Emel'yanova et al. ; Bottje and Carstens ). A reduction in the apparent P/O ratio in the liver of the food‐deprived fish is consistent with previous studies of chickens (Bobyleva‐Guarriero et al.…”

Section: Resultsmentioning

confidence: 99%

Simultaneous measurement of mitochondrial respiration and ATP production in tissue homogenates and calculation of effective P/O ratios

Salin

Villasevil

Auer

et al. 2016

Physiological Reports

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The use of tissue homogenate has greatly aided the study of the functioning of mitochondria. However, the amount of ATP produced per oxygen molecule consumed, that is, the effective P/O ratio, has never been measured directly in tissue homogenate. Here we combine and refine existing methods previously used in permeabilized cells and isolated mitochondria to simultaneously measure mitochondrial ATP production (JATP) and oxygen consumption (JO2) in tissue homogenate. A major improvement over existing methods is in the control of ATPases that otherwise interfere with the ATP assay: our modified technique facilitates simultaneous measurement of the rates of “uncorrected” ATP synthesis and of ATP hydrolysis, thus minimizing the amount of tissue and time needed. Finally, we develop a novel method of calculating effective P/O ratios which corrects measurements of JATP and JO2 for rates of nonmitochondrial ATP hydrolysis and respiration, respectively. Measurements of JATP and JO2 in liver homogenates from brown trout (Salmo trutta) were highly reproducible, although activity declined once homogenates were 2 h old. We compared mitochondrial properties from fed and food‐deprived animals to demonstrate that the method can detect mitochondrial flexibility in P/O ratios in response to nutritional state. This method simplifies studies examining the mitochondrial bioenergetics of tissue homogenates, obviating the need for differential centrifugation or chemical permeabilization and avoiding the use of nonmitochondrial ATPase inhibitors. We conclude that our approach for characterizing effective P/O ratio opens up new possibilities in the study of mitochondrial function in very small samples, where the use of other methods is limited.

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“…Contrary, in our late works [12, 14] with the aid to study the season changes in bioenergetics parameters of LLM, we removed the above mentioned substances from the isolation/incubation procedure. To better understand the mechanism(s) of the improving action of these compounds, in this work we investigated more thoroughly the effects of these reagents on the in vitro mitochondrial function of the lamprey liver.…”

Section: Resultsmentioning

confidence: 99%

On the Mechanism(s) of Membrane Permeability Transition in Liver Mitochondria of Lamprey,Lampetra fluviatilis L.: Insights from Cadmium

Belyaeva

Emelyanova

Коротков

et al. 2014

BioMed Research International

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Previously we have shown that opening of the mitochondrial permeability transition pore in its low conductance state is the case in hepatocytes of the Baltic lamprey (Lampetra fluviatilis L.) during reversible metabolic depression taking place in the period of its prespawning migration when the exogenous feeding is switched off. The depression is observed in the last year of the lamprey life cycle and is conditioned by reversible mitochondrial dysfunction (mitochondrial uncoupling in winter and coupling in spring). To further elucidate the mechanism(s) of induction of the mitochondrial permeability transition pore in the lamprey liver, we used Cd2+ and Ca2+ plus Pi as the pore inducers. We found that Ca2+ plus Pi induced the high-amplitude swelling of the isolated “winter” mitochondria both in isotonic sucrose and ammonium nitrate medium while both low and high Cd2+ did not produce the mitochondrial swelling in these media. Low Cd2+ enhanced the inhibition of basal respiration rate of the “winter” mitochondria energized by NAD-dependent substrates whereas the same concentrations of the heavy metal evoked its partial stimulation on FAD-dependent substrates. The above changes produced by Cd2+ or Ca2+ plus Pi in the “winter” mitochondria were only weakly (if so) sensitive to cyclosporine A (a potent pharmacological desensitizer of the nonselective pore) added alone and they were not sensitive to dithiothreitol (a dithiol reducing agent). Under monitoring of the transmembrane potential of the “spring” lamprey liver mitochondria, we revealed that Cd2+ produced its decrease on both types of the respiratory substrates used that was strongly hampered by cyclosporine A, and the membrane potential was partially restored by dithiothreitol. The effects of different membrane permeability modulators on the lamprey liver mitochondria function and the seasonal changes in their action are discussed.

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Peculiarities of functioning of liver mitochondria of the river lamprey Lampetra fluviatilis and the common frog Rana temporaria at periods of suppression and activation of energy metabolism

Cited by 7 publications

References 17 publications

David and Goliath: A Mitochondrial Coupling Problem?

David and Goliath: A Mitochondrial Coupling Problem?

Simultaneous measurement of mitochondrial respiration and ATP production in tissue homogenates and calculation of effective P/O ratios

On the Mechanism(s) of Membrane Permeability Transition in Liver Mitochondria of Lamprey,Lampetra fluviatilis L.: Insights from Cadmium

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