Shigaeva 2013 Abstract MiP2013

Shigaeva M, Gorbacheva O, Venediktova NI, Shigaev AS, Mironova GD (2013) The role of mitochondrial ATP-dependent potassium channel in the adaptation of organism to stress. Mitochondr Physiol Network 18.08.

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Shigaeva M, Gorbacheva O, Venediktova NI, Shigaev AS, Mironova GD (2013)

Event: MiP2013

It is known that different people and animals within the same species have different resistance to the stress damage. It is believed that these differences are largely genetically determined or acquired during the life of the differences in the activity of the stress system implementing the organism's response to stress-factor. Our objective was to determine the role of mitochondrial ATP-dependent potassium channel (mtKATP), which plays a key role in protecting the myocardium from ischemia [1], in protecting of the organism against some types of stress and adaptation to it.

The work was carried out on heart and liver mitochondria of rats of different genetic lines. To perform the first part of the study we selected purebred white rats having high and low resistance to acute hypoxic stress. Part of the low resistant animals were then artificially adapted to acute hypobaric hypoxia. The second part of the work was carried out on rats Wistar and August lines, having different resistance to the stress damage of the circulatory system [2] and to hypoxia [3] (August rats are resistant to stress influences, Wistar rats are less resistant).

When using outbred rats we have shown that the rate of ATP-dependent potassium transport was higher (by 15% in liver mitochondria and 30% in heart mitochondria) in mitochondria of high resistant to hypoxia rats compared with a low resistance. In adapted to oxygen deficiency rats rate of ATP-dependent potassium transport in mitochondria of both tissues is increased by 45-50%. It is accompanied by a decrease in the amount of K+ in the mitochondria of both tissues by an average of 30%, which may indicate the activation also K+/H+ - antiporter in mitochondria. Thus, potassium cycle in mitochondria activated. The same effect was observed in the study of potassium transport in mitochondria of rats Wistar and August lines. In more resistant to stress August line rats potassium uptake into the mitochondria via mtKATP and potassium amount is significantly higher compared to Wistar line rats.

High rate of mitochondrial potassium transport led to a marked reduction (by 25-30%) the rate of generation of H2O2 in the mitochondria. We presume that the effect of reducing the formation of reactive oxygen species in the mitochondria as a result of the activation mtKATP may mediate the positive effect of hypoxic training as well as genetic resistance to oxidative stress.

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Affiliations and author contributions

1 - Institute of Theoretical and Experimental Biophysics RAS, Pushchino, Russia;

2 - Puschino State Natural-Science Institute, Russia;

3 - Institute of mathematical problem of biology RAN, Pushchino, Russia.

Email: shigaeva-marija@rambler.ru

Supported by grants RFBR №12-04-31640mol_a, RFBR №12-04-32187mol_a, RFBR №10-04-00920a, DPNNiT № 4.3010.2011.

References

1. Gross G, Auchampach J (1992) Role of ATP dependent potassium channels in myocardial ischaemia. Cardiovasc Res 26: 1011-1016.
2. Belkina LM, Kirillina TN, Pshennikova MG, Arkhipenko YV (2002) August rats are more resistant to arrhythmogenic effect of myocardial ischemia and reperfusion than Wistar rats. Bull Exp Biol Med 133: 540-543. Russian.
3. Pshennikova MG, Belkina LM, Bakhtina LY, Baida LA, Smirin BV, Malyshev IY (2001) HSP70 stress proteins, nitric oxide, and resistance of August and Wistar rats to myocardial infarction. Bull Exp Biol Med 132: 741-743. Russian.