Quantitative analysis of the electrogenic ion exchange current using the cell dialysis method in the isolated cardiac myocytes.

使用细胞透析方法对离体心肌细胞中的生电离子交换电流进行定量分析。

• 批准号: 63480106
• 负责人: NOMA Akinori
• 金额: $ 4.1万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63480106/
• 关键词: single cardiac myocyte; Na; Ca exchange; ion exchange; intracellular Ca; patch clamp technique; Na@Ca交換機転; 単一心室筋細胞; イオンフラックス; Na-Ca交換機転

The intracellular Ca^<2+> concentration is lower by 10^4 than the extracellular Ca^<2+> concentration. This concentration gradient is essential to achieve various kinds of cell functions, such as the muscle contraction, and electrical activity of the cell. The Na/Ca exchange mechanism is mainly responsible for pumping out Ca^<2+> which enters the cardiac muscle during the systolic period. The aim of our project is to determine the stoichiometry of the Na/Ca exchange by recording the Na/Ca exchange current. We clarified that the intracellular ion concentrations may change, if we stimulate the Na/Ca exchange continuously. Therefore, we used a holding potential which is equal to the theoretical equilibrium potential for the 3Na:1Ca exchange. The reversal potential of the Na/Ca exchange current were successfully measured at various external Na^+ and Ca^<2+> concentrations. The reversal potential was in agreement with the theoretical values of the 3Na:1Ca exchange.

细胞内Ca^<2+>浓度比细胞外Ca^<2+>浓度低10^4倍。这种浓度梯度对于实现各种细胞功能，例如细胞的肌肉收缩和电活动是必不可少的。Na/Ca交换机制主要负责在收缩期泵出进入心肌的Ca^2+。我们的项目的目的是通过记录Na/Ca交换电流来确定Na/Ca交换的化学计量。我们阐明，细胞内离子浓度可能会发生变化，如果我们不断刺激Na/Ca交换。因此，我们使用的保持电位等于3 Na：1Ca交换的理论平衡电位。在不同的Na^+和Ca^<2+>浓度下，成功地测量了Na/Ca交换电流的反转电位。反转电位与3 Na：1Ca交换的理论值一致。

项目成果

Suppl.2: "9" 1988. 149-152.

增刊2：“9”1988。149-152。

Matsuoka S,Ehara T.,Noma A.: "Reversal potential of the Na-Ca exchange current in the cardiac myocyte of the guinea pig." Biomedical Research.

Matsuoka S、Ehara T.、Noma A.：“豚鼠心肌细胞中 Na-Ca 交换电流的反转电位。”

Ehara T.;Matsuoka S.;Noma A.: Journal of Physiology. in press. (1989)

Ehara T.；Matsuoka S.；Noma A.：生理学杂志。

Noma A.;Ehara T.: "Electrogenic Na-K pump and Na-Ca exchange in cardiac muscle.In ISOLATED ADULT CARDIOMYOCYTES" G.Isenberg, (1989)

Noma A.；Ehara T.：“心肌中的电钠钾泵和钠钙交换。在分离的成年心肌细胞中”G.Isenberg，(1989)

Ehara T., Matsuoka S., Noma A.: "Measurement of reversal potential of Na^+-Ca^<2+> exchange current in single guinea-pig ventricular cells." Journal of Physiology 410:227-249 1989.

Ehara T.、Matsuoka S.、Noma A.：“测量单个豚鼠心室细胞中 Na^ -Ca^<2 > 交换电流的反转电位。”