Journal archive > 2005 > N2, March-April

The influence of nitric oxide donors on Ca2+-uptake in rat heart and liver mitochondria

O. V. Akopova, V. F. Sagach

The influence of NO donors, nitroglycerin (NG) and sodium nitroprusside (SNP), on Ca2+-uptake in rat heart and liver mitochondria is studied. It is shown that in vivo NG causes a rapid dose-dependent increase of Ca2+-uptake in rat heart mitochondria most pronounced at 0.5–1.0 mg/kg weight NG. This sharp increase of Ca2+-uptake is not accounted for by changes in membrane potential of mitochondria (??m) because ??m is not influenced by less than 1.0 mg/kg NG, and moreover, decrease by ~30% is observed at 1.0–1.5 mg/kg NG.

In vitro, on the contrary, a concentration-dependent decrease in Ca2+-uptake caused by NG as well as SNP is observed together with simultaneous decrease of ??m and concentration-dependent release of Ca2+ from mitochondria via Ca2+-uniporter as the result of partial depolarisation of mitochondrial inner membrane.

The data obtained give an evidence that increase in Ca2+-uptake caused by NO donor in vivo takes place independently of changes in ??m and also is not resulted from a direct action of NO on Ca2+-uniporter. These observations allow us to suppose that activation of mitochondrial Ca2+-uptake in vivo and corresponding decrease in cytosolic Ca2+ concentration could be involved in vasodilatory action of nitric oxide.

Recieved: 2004-11-12

Published at the site: 2005-03-03

The original article in Russian is available for download in PDF format.

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