在人类心室肌细胞模型的单维链中传播反极化的离子机制
Yukiko Himeno1, Yixin Zhang1, Suzuka Enomoto1
1Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan.
International journal of molecular sciences
|October 28, 2023
概括
这项研究模拟了肌细胞中的心脏再极化传播. 它发现特定的离子通道活动,特别是向内调整器通道 (IK1),驱动这种再极化波,有助于心脏放松.
科学领域:
- 心脏电生理学 心脏电生理学
- 计算生物学 计算生物学
- 数学建模的数学建模
背景情况:
- 心脏组织中的反极化传播在理论上和实验上是建议的,但很难量化.
- 了解复极化对放松的贡献对于心脏功能至关重要.
- 正常的心脏再极化发生在膜激发期间,这对单独研究提出了挑战.
研究的目的:
- 建立一个数学模型来研究心脏肌细胞中的再极化传播.
- 为了研究背后的离子机制再极化波的传播.
- 为了确定复极化对心脏放松的贡献.
主要方法:
- 开发了一种由600个肌细胞组成的1D链的数学模型.
- 在平原附近的平衡潜力处稳定肌细胞使用晚期电流 (INaL).
- 应用超极化刺激来诱导和观察再极化传播.
主要成果:
- 成功诱导并观察到以12厘米/秒的速度传播的再极化.
- 确定了关键的离子机制:INaL和L型电流 (ICaL) 失活,以及快速延迟整流电流 (IKr) 和IK1激活.
- 证明了IK1的再生激活通过间隙结合驱动了顺序的肌细胞再极化.
结论:
- 再极化在特定条件下可以在心脏组织中独立传播.
- 内向整流器通道 (IK1) 在启动和维持再极化波中起着至关重要的作用.
- 这种传播机制为心脏放松动态提供了洞察力.
相关概念视频
Cardiac Action Potential
1.6K
Cardiac action potentials are essential for proper heart function, enabling the rhythmic contractions needed for adequate blood circulation. Nodal cells and Purkinje fibers, specialized for electrical conduction, generate these action potentials.
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
1.6K
Electrophysiology of Normal Cardiac Rhythm
5.3K
The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase...
5.3K
Mechanism of Cardiac Arrhythmias
929
Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms.
929
Propagation of Action Potentials
5.9K
The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron.
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
5.9K
Generation of Action Potential in Skeletal Muscles
4.6K
Every cell in the body maintains a membrane potential due to an uneven distribution of positive and negative charges across its plasma membrane. The membrane potential is measured in millivolts and quantifies the difference in charge across the membrane.
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the...
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the...
4.6K
Mechanically-gated Ion Channels
6.4K
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
6.4K


