在心力衰竭中,细胞内Na(+) 度升高,但Na/K功能没有变化
Sanda Despa1, Mohammed A Islam, Christopher R Weber
1Department of Physiology, Loyola University Chicago, Maywood, IL 60153, USA.
Circulation
|May 30, 2002
概括
心力衰竭 (HF) 中细胞内的升高是由于流量增加,而不是酸功能受损. 这种的增加会影响细胞调节,并可能限制HF患者的收缩功能障碍.
科学领域:
- 心血管生理学心血管生理学
- 细胞电生理学 细胞电生理学
- 心脏衰竭病理生理学 病理生理学
背景情况:
- 细胞内度 ([Na(+) ](i)) 是通过Na/Ca交换 (NCX) 机制的心脏功能的关键调节者.
- 在心力衰竭 (HF) 中,NCX的上调可能会放大改变[Na+]对心脏收缩性和电活动的影响.
研究的目的:
- 研究心力衰竭中细胞内度升高背后的机制.
- 确定流入和流出通道在调节HF肌细胞中的[Na(+) ](i) 中的作用.
主要方法:
- 测量细胞内度 ([Na(+) ](i)) 使用控制和HF模型中的子腹腔肌细胞中的结佐异甲酸盐.
- 评估Na/K介导的挤出速率 (Vmax和Km),以评估功能.
- 通过对四毒素敏感通道量化静止的流入.
主要成果:
- 与对照肌细胞 (6.6±0.5 mmol/L) 相比,HF肌细胞 (9.7±0.7 mmol/L) 的静止细胞内度显著更高.
- 在HF中,Na/K功能 (Vmax和Km) 没有变化,表明正常的挤出能力.
- 休息中的流量在HF肌细胞中翻了一番,主要是通过对四毒素敏感的通路,解释了[Na(+) ](i) 的升高.
结论:
- 在HF中细胞内的升高是由于扩张性流量增加而导致的,与正常的Na/K-ATPase活性.
- 在HF中[Na(+) ](i) 的增加,以及改变的过渡物和作用潜力,影响细胞处理和NCX活性.
- 细胞内度升高可能通过减轻心力衰竭中严重的收缩功能障碍发挥保护作用.
关键词:
非编程性的非编程性.相关概念视频
The Resting Membrane Potential
Overview
Resting Membrane Potential
The relative difference in electrical charge, or voltage, between the inside and the outside of a cell membrane, is called the membrane potential. It is generated by differences in permeability of the membrane to various ions and the concentrations of these ions across the membrane.
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...
Resting Potential Decay
The resting membrane potential of a neuron (-70mV) is sustained due to the selective ion permeability of the membrane. At the resting potential, the membrane is slightly permeable to ions like sodium (Na+) and chloride (Cl−) and highly permeable to potassium ions (K+). Differences in the ions' concentration inside the cell compared to the outside are maintained by membrane transport proteins like channels and pumps.
At rest, the K+ is the main ion that moves across the membrane through...
At rest, the K+ is the main ion that moves across the membrane through...
pH Regulation in Cells
pH plays a critical role in maintaining normal cellular activities. It helps maintain the structure and function of various proteins, dictates the charge on cellular membranes, and is crucial for metabolic reactions inside the cell. Moreover, cells use the energy from the proton motive force to generate ATP.
Cytosolic pH
Under physiological conditions, the cytosolic pH is slightly more acidic than the extracellular pH. However, cells must prevent further acidification of their cytosol to...
Cytosolic pH
Under physiological conditions, the cytosolic pH is slightly more acidic than the extracellular pH. However, cells must prevent further acidification of their cytosol to...
Roles of Electrolytes: Sodium and Potassium
Sodium plays a crucial role in maintaining fluid and electrolyte balance and overall bodily homeostasis. Sodium balance is primarily regulated by kidney function, which adjusts sodium elimination to match dietary intake and maintain proper electrolyte levels. Sodium is the most abundant cation in the extracellular fluid (ECF) and is found in salts such as sodium chloride (NaCl) and sodium bicarbonate (NaHCO3). Although cellular plasma membranes are relatively impermeable to sodium, its role in...
Regulation of Sodium and Potassium
The regulation of sodium and potassium ion concentrations in the human body is a complex process governed primarily by hormones such as aldosterone, antidiuretic hormone (ADH), and atrial natriuretic peptide (ANP).
Sodium Regulation
Sodium ions make up approximately 90% of extracellular cations, with a normal blood plasma concentration of 136–148 mEq/L. A decrease in blood volume and pressure triggers the release of renin from granular cells in the juxtaglomerular complex (JGC), primarily in...
Sodium Regulation
Sodium ions make up approximately 90% of extracellular cations, with a normal blood plasma concentration of 136–148 mEq/L. A decrease in blood volume and pressure triggers the release of renin from granular cells in the juxtaglomerular complex (JGC), primarily in...


