軽度および重度の実験性心不全における急性中性エンドペプチダース抑制に対する腎応答
H H Chen1, J A Schirger, W L Chau
1Cardiorenal Research Laboratory, Division of Cardiovascular Diseases and Department of Physiology, Mayo Clinic and Foundation, Rochester, MN 55905, USA. chen.horng@mayo.edu
Circulation
|December 14, 1999
まとめ
中性エンドペプチダース (NEP) 阻害は,軽度の閉塞性心不全 (CHF) の腎臓機能を改善します. このアプローチは,ナトリウム排出と腎臓の血流を増加させ,初期段階のCHFに対する潜在的な治療戦略を提供します.
科学分野:
- 心臓器官の生理学について
- 薬理学 薬理学とは
背景:
- 中性エンドペプチダゼ24.11 (NEP) は,ANPのようなナトリウレチンペプチドを分解する.
- 軽度の閉塞性心不全 (CHF) は,レニン・アニオテンシン・アルドステロン系 (RAAS) の活性化なしにANPの増加を示します.
- 重度のCHFは,ナトリウム保持と同活性化されたANPとRAASを含む.
研究 の 目的:
- NEP阻害剤カンドオクサトリラットの急性心経性効果を,さまざまな段階のCHFを有する犬で調査する.
- 軽度のCHFと重度のCHFにおけるNEP阻害の有効性を比較し,AT(1) 受容体対抗性の影響を評価する.
主な方法:
- 麻酔を受けた犬の4つのグループが研究されました:正常な,軽度のCHF,重度のCHF,および慢性的なAT(1) 受容器対抗性の重度のCHF.
- 軽度および重度のCHFは,急速な心室ペースによって誘発された.
- カンドオキサトリラトの急性心経作用は,尿中のナトリウム分泌量,球の濾過率,腎臓の血流量,ANP/cGMP分泌量を測定することによって評価されました.
主要な成果:
- NEPの阻害は,コントロールと重度のCHFと比較して,軽度のCHFで尿中のナトリウム分泌とグルメルーラ濾過率を著しく増加させました.
- 腎臓の血流は増加し,腎血管抵抗と遠管管状ナトリウム再吸収は軽度のCHFにおいてのみ減少した.
- 尿中のANPとcGMPの分泌は,軽度のCHFで最高であったが,これらの効果は重度のCHFでは弱まり,AT(1) 受容器の対抗によって改善されませんでした.
結論:
- 急性NEP阻害は,軽度のCHFで腎臓の血動力学とナトリウム分泌を著しく高めます.
- これらの発見は,選択的なANP活性化による早期段階のCHFにおける腎機能の改善のためのNEP抑制の治療的可能性を強調しています.
- NEP阻害の有益な腎的効果は重度のCHFでは低下し,AT(1) 受容体経由でRAASを阻害することで回復しません.
関連する概念動画
01:30Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors
Angiotensin-converting enzyme (ACE), a vital component of the renin-angiotensin-aldosterone system, is abundant in lung endothelial cells. ACE converts the inactive decapeptide, angiotensin I, into the active octapeptide, angiotensin II. This potent vasoconstrictor narrows blood vessels, increasing resistance to blood flow and elevating blood pressure. Angiotensin II also stimulates aldosterone production, encouraging kidney cells to reabsorb more sodium and water from urine, thereby increasing...
01:22Heart Failure Drugs: Diuretics
Heart failure and kidney perfusion are interconnected in a complex way. Reduced renal perfusion and venous congestion are two significant factors that contribute to renal dysfunction in heart failure. The kidneys, primarily responsible for fluid balance in the body, are adversely affected due to compromised cardiac output and increased venous pressure. In response to reduced renal perfusion, the kidneys activate neurohumoral mechanisms to restore balance. However, these mechanisms can be...
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral...
01:22Heart Failure Drugs: β-Blockers
β-adrenergic antagonists, commonly known as β-blockers, block the effects of sympathetic neurotransmitters such as noradrenaline (NA) and adrenaline (ADR). They have several beneficial effects in heart failure treatment. They reduce heart rate, the force of contraction, and cardiac muscle relaxation. They also slow the atrial-ventricular conduction rate and raise the threshold for arrhythmias. The concentration of β-blockers determines their effects on bronchodilation, vasodilation, and...
01:29Heart Failure II: Pathophysiology
Systolic Heart Failure and Compensatory MechanismsSystolic heart failure (also termed HFrEF, Heart Failure with Reduced Ejection Fraction) is the most prevalent type of heart filure. It results in a decreased volume of blood being pumped from the ventricle. The aortic arch and carotid sinuses have baroreceptors that detect reduced blood pressure, triggering the sympathetic nervous system (SNS) to release epinephrine and norepinephrine. Initially, this response aims to boost heart rate and...
01:30Heart Failure V: Medical Management
Medical Management of Acute Decompensated Heart Failure (ADHF)The primary goals of therapy for patients hospitalized with acute decompensated heart failure (ADHF) include:Relieving symptomsOptimizing volume statusSupporting oxygenation and ventilationMaintaining cardiac output (CO) and end-organ perfusionIdentifying and addressing the cause of ADHFPreventing complicationsProviding patient education on factors precipitating HF exacerbationPlanning for dischargeOngoing monitoring and assessment...