Reduced calcium tolerance in rat cardiomyocytes after myocardial infarction

被引：26

作者：

Sjaastad, I ^{[1
]}

Bentzen, JG ^{[1
]}

Semb, SO ^{[1
]}

Ilebekk, A ^{[1
]}

Sejersted, OM ^{[1
]}

机构：

[1] Univ Oslo, Ullevaal Univ Hosp, Expt Med Res Inst, N-0407 Oslo, Norway

来源：

ACTA PHYSIOLOGICA SCANDINAVICA | 2002年 / 175卷 / 04期

关键词：

heart failure; intra/extracellular ions; ion exchangers; myocardial infarction; Na/Ca-exchanger;

D O I：

10.1046/j.1365-201X.2002.00999.x

中图分类号：

Q4 [生理学];

学科分类号：

071003 [生理学];

摘要：

During ischaemia and reperfusion the intracellular Na+ concentration is elevated in the cardiomyocytes and the cells are depolarized, both favouring reverse mode Na,Ca-exchange loading of the cell with Ca2+ . We examined whether cardiomyocytes from rats with congestive heart failure (CHF) and younger rats (HINCX) which both have a high expression of the Na,Ca-exchanger protein (NCX) showed reduced tolerance to extracellular Ca2+ . The CHF was induced in Isofluran anaesthetized rats by left coronary artery ligation. Isolated cardiomyocytes were loaded with Fura-2AM and 140 mm Na+ and exposed to 0.05 mm Ca2+ . Expression of the Na,Ca-exchanger protein was analysed. Fura-2 340/380 ratio rose more rapidly in HINCX and CHF than in SHAM, and the rise was abolished by Ni2+ . Hypercontracture developed more frequently in HINCX and CHF than in SHAM cells. The amount of NCX was 54% higher in HINCX and 76% higher in CHF compared with SHAM. Na+ -loaded cardiomyocytes from CHF and HINCX rats are more susceptible to Ca2+ overload than SHAM cells because of the increased capacity for Na,Ca-exchange.

引用

页码：261 / 269

页数：9

共 30 条

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