Related Experiment Video
Updated: Aug 8, 2026
10:18
Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model
Published on: June 29, 2014
[Renin-angiotensin system and heart failure]
Jun Suzuki1, Masatsugu Horiuchi
1Second Department of Internal Medicine, First Department of Medical Biochemistry, Ehime University School of Medicine.
Nihon Rinsho. Japanese Journal of Clinical Medicine
|May 21, 2003
Summary
The cardiac renin-angiotensin system impacts heart failure. While Angiotensin II type 1 (AT1) receptor activation causes damage, the protective role of Angiotensin II type 2 (AT2) receptors in cardiac hypertrophy and fibrosis remains debated.
Area of Science:
- Cardiovascular Physiology
- Molecular Cardiology
- Renal Physiology
Context:
- The local renin-angiotensin system (RAS) in cardiac tissue plays a crucial role in the development of cardiac hypertrophy and heart failure.
- Angiotensin II type 1 (AT1) receptor activation is implicated in detrimental processes including vasoconstriction, cellular growth, oxidative stress, aldosterone release, and fibrosis.
- Emerging evidence suggests the Angiotensin II type 2 (AT2) receptor may offer cardioprotective benefits by opposing AT1 receptor actions.
Purpose:
- To review the current understanding of the cardiac renin-angiotensin system's role in heart failure.
- To critically evaluate the evidence surrounding the function of AT2 receptor signaling in cardiac hypertrophy and fibrosis.
Summary:
- The cardiac renin-angiotensin system is a key mediator in the pathophysiology of heart failure.
- AT1 receptor stimulation drives adverse cardiac remodeling and dysfunction.
- The precise role of AT2 receptor signaling in counteracting these effects and its implications in cardiac hypertrophy and fibrosis are still under investigation and subject to ongoing debate.
Impact:
- This review consolidates evidence on the cardiac RAS in heart failure, highlighting the complex and sometimes contradictory roles of its components.
- Understanding the balance between AT1 and AT2 receptor signaling is critical for developing novel therapeutic strategies for heart failure.
- Further research into AT2 receptor pathways may reveal new targets for mitigating cardiac hypertrophy and fibrosis.
Related Concept Videos
01:33Hormonal Regulation
The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream.
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...
01:25Antihypertensive Drugs: Direct Renin Inhibitors
The renin-angiotensin-aldosterone system (RAAS) is an intricate physiological pathway involving numerous enzymes and hormones, including renin, angiotensin-converting enzyme (ACE), angiotensin I and II, and aldosterone. Imbalances within this system increase the production of angiotensin II and aldosterone. Increased angiotensin II levels promote vasoconstriction and blood pressure elevation. Concurrently, higher aldosterone levels stimulate sodium and water reabsorption in the kidneys,...
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...
01:29Heart 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...