トランスジェニックマウスのアルドステロン誘発冠動脈機能障害は,血管の滑らかな筋肉細胞のカルシウム活性化カリウム (BKCa) チャンネルを巻き込む
Marie-Lory Ambroisine1, Julie Favre, Patricia Oliviero
1Inserm U689 and Paris Diderot University, Paris, France.
Circulation
|November 7, 2007
まとめ
マウスにおけるアルドステロンの過剰発現は,血管内のカルシウム活性化カリウム (BKCa) 経路を減少させ,冠動脈のリラックスを損なう. これは,BKCaチャネルが心血管疾患の潜在的な治療標的であることを示唆しています.
科学分野:
- 心血管生理学 心血管の生理学
- 分子生物学は分子生物学である.
- 薬理学 薬理学とは
背景:
- アルドステロン合成酵素が心筋細胞で過剰発現すると,酸化窒素から独立した冠動脈機能不全が生じます.
- カルシウム活性化カリウム (BKCa) チャンネルは,血管の滑らかな筋肉細胞 (VSMC) のリラックスに不可欠です.
研究 の 目的:
- アルドステロンがVSMCにおけるBKCaチャネル発現または機能を変化させるかどうかを調査する.
- アルドステロン誘発の冠動脈機能不全におけるBKCaチャネルの役割を決定する.
主な方法:
- 孤立したマウス冠動脈のセグメントは,ワイヤミオグラフィで使用されました.
- アセチルコリン誘発のリラクゼーションは,様々な阻害剤 (ディクロフェナック,カリブドトキシン,アパミン,イベリトキシン) の有無と有無で評価されました.
- 心臓と冠動脈におけるBKCaチャネル発現は,qPCRとウエスタン・ブロットで定量化され,マウスの培養型の大動脈VSMCでも効果が研究されました.
主要な成果:
- アセチルコリン媒介の冠動脈リラクゼーションは,MASマウスでは著しく減少し,スピロノラクトンによって防止されました.
- BKCaチャネルサブユニット発現 (αとβ1) は,マウスマウスハートと冠動脈のMASで減少しました.
- アルドステロンは,培養されたVSMCのBKCa発現を低下させ,スピロノラクトンによってブロックされた効果です.
結論:
- アルドステロンの過剰発現はVSMCのBKCa発現とBKCa依存の冠動脈リラクゼーションを変化させます.
- これらの変化は,心臓血管疾患におけるアルドステロンの有害な効果に寄与する可能性があります.
- BKCaチャネルは,心血管疾患の潜在的な治療目標です.
関連する概念動画
Muscle Contraction
6.8K
In skeletal muscles, acetylcholine is released by nerve terminals at the motor endplate—the point of synaptic communication between motor neurons and muscle fibers. The binding of acetylcholine to its receptors on the sarcolemma allows entry of sodium ions into the cell and triggers an action potential in the muscle cell. Thus, electrical signals from the brain are transmitted to the muscle. Subsequently, the enzyme acetylcholinesterase breaks down acetylcholine to prevent excessive...
6.8K
Chemical Synapses
9.5K
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
9.5K
Ligand-Gated Ion Channel Receptor: Gating Mechanism
4.6K
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
4.6K
Chemical Synapses
10.9K
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
10.9K
Smooth Muscle Contraction
8.7K
Smooth muscle contraction is a complex process vital for various bodily functions, from maintaining blood vessel tension to facilitating the movement of food through the digestive tract. Unlike striated muscles, smooth muscle contraction begins more slowly and lasts longer.
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
8.7K
Antihypertensive Drugs: Action of Calcium Channel Blockers
2.4K
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,...
2.4K


