アトリオナトリウレチンペプチドは,心臓のナトリウムチャネルをカルシウム伝導チャネルに変換します
1Department of Physiology, University of Pennsylvania, Philadelphia 19104-6085.
Science (New York, N.Y.)
|February 23, 1990
まとめ
アトリオナトリウレティックペプチド (ANP) は,心臓のナトリウムとカルシウム経路を抑制する. この動作には,ナトリウムチャネルの変化が含まれる可能性があります.
科学分野:
- 心血管生理学 心血管の生理学
- 分子心臓病学 分子心臓病学
- イオンチャネル機能
背景:
- アトリアルナトリウレチンペプチド (ANP) は,細胞外液体量と血圧を調節する.
- ANPは,流体量が増加したため,心房細胞から放出されます.
- 既知の効果には,腎臓によるナトリウム吸収の減少が含まれています.
研究 の 目的:
- ANPが心臓のイオンチャネルに及ぼす直接的な影響を調査する.
- ANPが心室筋細胞のナトリウムとカルシウム電流に影響を与えるメカニズムを解明する.
主な方法:
- 電気生理学的記録 (パッチクランプ) は,ラットとコウモリの心室筋細胞で行われました.
- 特定のイオン電流 (ナトリウムとカルシウム) は,ANPの存在と不在で測定されました.
主要な成果:
- ANPは,心室筋細胞におけるカルシウムとナトリウムの両方の流れを著しく抑制しました.
- ナトリウム電流抑制は,カルシウムへのチャネル透過性の増加と関連しており,運動学やテトロドトキシン感受性の変化はなかった.
- ANP誘発のチャネル調節は,カチオンの選択性部位の変化を伴う可能性があります.
結論:
- ANPは心臓のイオンチャネル機能に直接影響を及ぼし,特にナトリウムとカルシウム電流を抑制します.
- このメカニズムは,カルシウムイオンに対するナトリウムチャネルの選択性の潜在的な変化を含む.
- このイオン電流の抑制と細胞興奮性の低下は,ANP分泌の調節に寄与する可能性がある.
関連する概念動画
01:26Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
01:12Mechanically-gated Ion Channels
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...
01:21G-Protein Gated Ion Channels
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...
Sensory organs,...
01:27Transducer Mechanism: Enzyme-Linked Receptors
Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
Major types that are helpful drug targets include:
01:18Antihypertensive Drugs: Action of Calcium Channel Blockers
Calcium ions are essential to contract smooth muscle cells in blood vessels. They enter these cells through voltage-dependent calcium channels, specifically L-type calcium channels in the cell membrane. These L-type calcium channels are integral to the excitation-contraction coupling process in smooth muscle. When a stimulus is received by smooth muscle cells, their membrane depolarizes. This alteration in membrane potential instigates the opening of L-type calcium channels. As a result,...
01:30Cardiac Action Potential
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