シトソリックCa2+) 負荷の減少と,ギニアピッグの izolated hearts の冷蔵庫での心不全後の心機能の改善
D F Stowe1, S G Varadarajan, J An
1Anesthesiology Research Laboratory, Department of Anesthesiology, Medical College of Wisconsin, and Veterans Affairs Medical Center, Milwaukee, WI, USA.dfstowe@mcw.edu
Circulation
|September 7, 2000
まとめ
心筋梗塞 (CP) は,低温貯蔵中のカルシウム負荷を減少させ,再加熱時に心臓の機能を改善します. この研究は,減量された下痢性カルシウムと冷蔵後の心圧の回復と効率の改善を関連付けています.
科学分野:
- 心血管生理学 心血管の生理学
- 細胞生物学 細胞生物学
- バイオケミストリー バイオケミストリー
背景:
- 低体温は心臓を保護しますが,再加熱中に有害なカルシウム (Ca2+) 負荷と機能障害につながる可能性があります.
- 細胞溶液Ca2+の動態を理解することは,低温下での心臓保存戦略の最適化に不可欠です.
研究 の 目的:
- 寒冷保存期間およびその後の細胞溶液Ca2+レベルの変化と心臓機能の関連性を調査する.
- 低温保存された心臓におけるCa2+の取り扱いと機能回復に関する,標準的なKrebs-Ringer (KR) 溶液と,心筋麻痺 (CP) の効果を比較する.
主な方法:
- 豚の心臓は,冷却中にKR溶液またはCP溶液を注入し,3°Cで冷蔵庫で4時間保存した.
- 左心室圧 (LVP),dP/dt,酸素消費,心臓の効率,および細胞溶液Ca2+トランジント (インド-1光を用いて) をモニタリングした.
- 冷凍保存前,冷凍保存中,冷凍保存後の測定と,その後の再注血が行われました.
主要な成果:
- KR単独での冷却はダイアストリックと相性Ca2+を増加させ,CPは相性Ca2+を抑制し,ダイアストリックCa2+の上昇を弱めた.
- CP後の再輸は,KRと比較して,相性Ca2+ (86%で20分) が著しく高く,ダイアストリックCa2+が保存された.
- CPで保存された心臓は,再注血中にLVPの優れた回復 (126%と50%),酸素消費 (23%以上),心臓効率 (38%以上) を示しました.
結論:
- 心筋梗塞は,冷蔵庫でのダイアストリックCa2+の増加を効果的に軽減します.
- 貯蔵後の低静脈および高静脈のCa2+によって特徴づけられるCPのCa2+負荷の減少は,再注射時に心臓機能を大幅に改善します.
関連する概念動画
Long-term Depression
Long-term depression, or LTD, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTD is the process of synaptic weakening that occurs over time between pre and postsynaptic neuronal connections. The synaptic weakening of LTD works in opposition to synaptic strengthening by long-term potentiation (LTP) and together are the main mechanisms that underlie learning and memory.
Calcium Ion Concentration Mechanism
If over time, all...
Calcium Ion Concentration Mechanism
If over time, all...
Ligand-gated Ion Channels
Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site.
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
Ligand-Gated Ion Channel Receptor: Gating Mechanism
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...
Heart Failure Drugs: Inotropic Agents
Positive inotropic agents are commonly used as the first line of treatment for heart failure. One such agent is digoxin, derived from the genus Digitalis, which has been known for centuries but effectively utilized since 1785. However, these cardiac glycosides can have potentially toxic effects due to their mechanism of action, which involves inhibiting Na+/K+-ATPase and increasing contractility. Digoxin is absorbed orally and distributed in various tissues, including the CNS. It has a long...
Antianginal Drugs: Calcium Channel Blockers and Ranolazine
Angina pectoris, a primary symptom of ischemic heart disease, requires careful pharmacological interventions. In this context, calcium channel blockers (CCBs) and ranolazine have emerged as crucial pharmacotherapeutic agents, providing deep insights into the complexities of angina management.
CCBs, a diverse class that includes dihydropyridines (nifedipine) and diphenylalkylamines (verapamil and diltiazem), exert their effect by blocking calcium channels in cardiac and smooth muscle cells. This...
CCBs, a diverse class that includes dihydropyridines (nifedipine) and diphenylalkylamines (verapamil and diltiazem), exert their effect by blocking calcium channels in cardiac and smooth muscle cells. This...
Myocarditis III: Medical Management
Myocarditis: Comprehensive Medical ManagementMyocarditis, the heart muscle inflammation, requires a comprehensive medical management strategy that addresses the underlying cause, provides supportive care, manages symptoms, and reduces cardiac workload.Infections and Autoimmune CausesAdminister appropriate antimicrobial therapy when an infectious agent causes myocarditis. For instance, penicillin treats infections caused by Group A Streptococcus. In cases where autoimmune processes are...


