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

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Elena A. Belyaeva ◽  
Larisa V. Emelyanova ◽  
Sergey M. Korotkov ◽  
Irina V. Brailovskaya ◽  
Margarita V. Savina
Keyword(s):  
Membrane Permeability ◽  
Cyclosporine A ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Liver Mitochondria ◽  
Nitrate Medium ◽  
Lampetra Fluviatilis ◽  
Mitochondrial Permeability

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 Pias the pore inducers. We found that Ca2+plus Piinduced 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 Piin 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.

scholarly journals Tissue Specific Sensitivity of Mitochondrial Permeability Transition Pore to Ca2+ Ions

2009 ◽  
Vol 52 (2) ◽  
pp. 69-72 ◽  
Author(s):  
René Endlicher ◽  
Pavla Křiváková ◽  
Halka Lotková ◽  
Marie Milerová ◽  
Zdeněk Drahota ◽  
...  
Keyword(s):  
Cyclosporine A ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Mitochondrial Swelling ◽  
Heart Mitochondria ◽  
Cell Protection ◽  
Tissue Specific ◽  
Mitochondrial Permeability

Ca2+-induced opening of the mitochondrial permeability transition pore (MPTP) is involved in induction of apoptotic and necrotic processes. We studied sensitivity of MPTP to calcium using the model of Ca2+-induced, cyclosporine A-sensitive mitochondrial swelling. Presented data indicate that the extent of mitochondrial swelling (dA520/4 min) induced by addition of 25 μM Ca2+ is seven-fold higher in liver than in heart mitochondria (0.564 ± 0.08/0.077± 0.01). The extent of swelling induced by 100 μM Ca2+ was in liver tree times higher than in heart mitochondria (0.508±0.05/ 0.173±0.02). Cyclosporine A sensitivity showed that opening of the MPTP is involved. We may thus conclude that especially at low Ca2+ concentration heart mitochondria are more resistant to damaging effect of Ca2+ than liver mitochondria. These finding thus support hypothesis that there exist tissue specific strategies of cell protection against induction of the apoptotic and necrotic processes.

scholarly journals The Effects of PK11195 and Protoporphyrin IX Can Modulate Chronic Alcohol Intoxication in Rat Liver Mitochondria under the Opening of the Mitochondrial Permeability Transition Pore

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1774
Author(s):  
Yulia Baburina ◽  
Irina Odinokova ◽  
Olga Krestinina
Keyword(s):  
Rat Liver ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Alcohol Exposure ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Chronic Alcohol ◽  
Mitochondrial Permeability

Decades of active research have shown that mitochondrial dysfunction, the associated oxidative stress, impaired anti-stress defense mechanisms, and the activation of the proapoptotic signaling pathways underlie pathological changes in organs and tissues. Pathologies caused by alcohol primarily affect the liver. Alcohol abuse is the cause of many liver diseases, such as steatosis, alcoholic steatohepatitis, fibrosis, cirrhosis, and, potentially, hepatocellular cancer. In this study, the effect of chronic alcohol exposure on rat liver mitochondria was investigated. We observed an ethanol-induced increase in sensitivity to calcium, changes in the level of protein kinase Akt and GSK-3β phosphorylation, an induction of the mitochondrial permeability transition pore (mPTP), and strong alterations in the expression of mPTP regulators. Moreover, we also showed an enhanced effect of PK11195 and PPIX, on the parameters of the mPTP opening in rat liver mitochondria (RLM) isolated from ethanol-treated rats compared to the RLM from control rats. We suggest that the results of this study could help elucidate the mechanisms of chronic ethanol action on the mitochondria and contribute to the development of new therapeutic strategies for treating the effects of ethanol-related diseases.

scholarly journals Carbenoxolon Is Capable to Regulate the Mitochondrial Permeability Transition Pore Opening in Chronic Alcohol Intoxication

2021 ◽  
Vol 22 (19) ◽  
pp. 10249
Author(s):  
Yulia Baburina ◽  
Irina Odinokova ◽  
Olga Krestinina
Keyword(s):  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Alcohol Intoxication ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
High Amplitude ◽  
Liver Mitochondria ◽  
Lag Phase ◽  
Mitochondrial Permeability ◽  
Rat Brain And Liver

Background: carbenoxolone, which is a derivative of glyceretic acid, is actively used in pharmacology for the treatment of diseases of various etiologies. In addition, we have shown carbenoxolone as an effective inducer of mitochondrial permeability transition pore in rat brain and liver mitochondria. Methods: in the course of this work, comparative studies were carried out on the effect of carbenoxolone on the parameters of mPTP functioning in mitochondria isolated from the liver of control and alcoholic rats. Results: within the framework of this work, it was found that carbenoxolone significantly increased its effect in the liver mitochondria of rats with chronic intoxication. In particular, this was expressed in a reduction in the lag phase, a decrease in the threshold calcium concentration required to open a pore, an acceleration of high-amplitude cyclosporin-sensitive swelling of mitochondria, as well as an increase in the effect of carbenoxolone on the level of mitochondrial membrane-bound proteins. Thus, as a result of the studies carried out, it was shown that carbenoxolone is involved in the development/modulation of alcohol tolerance and dependence in rats.

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