[Effect of nitric oxide donors on Ca2+-uptake in the rat heart and liver mitochondria].
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 (deltapsim) because deltapsim is not influenced by less than 1,0 mg/kg NG, and moreover, decrease by approximately 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 deltapsim 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 deltapsim 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.
Akopova
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Sagach
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D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000378:metabolism; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D005996:Nitroglycerin / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats
D020030:Nitric Oxide Donors; D009599:Nitroprusside; D009569:Nitric Oxide; D005996:Nitroglycerin; D002118:Calcium