Related Experiment Video

Updated: Jun 28, 2026

Impact of Intracardiac Neurons on Cardiac Electrophysiology and Arrhythmogenesis in an Ex Vivo Langendorff System
06:40

Impact of Intracardiac Neurons on Cardiac Electrophysiology and Arrhythmogenesis in an Ex Vivo Langendorff System

Published on: May 22, 2018

Feedback inhibition of catecholamine release by two different alpha2-adrenoceptor subtypes prevents progression of

Marc Brede1, Frank Wiesmann, Roland Jahns

  • 1Institut für Pharmakologie und Toxikologie, Universität Würzburg, Germany.

Circulation
|November 6, 2002
PubMed
Abstract

Insights

Alpha2A- and Alpha2C-adrenoceptors are crucial for preventing heart failure progression in mice and humans. Genetic variants in these receptors worsen heart failure outcomes, suggesting new therapeutic targets.

Area of Science:

  • Cardiovascular Research
  • Pharmacology
  • Genetics

Background:

  • Elevated norepinephrine is linked to increased mortality in chronic heart failure.
  • Alpha2-adrenoceptors regulate norepinephrine release, potentially impacting heart failure progression.

Purpose of the Study:

  • Investigate alpha2-adrenoceptor subtypes controlling norepinephrine release in heart failure.
  • Assess the role of alpha2-adrenoceptor subtypes in response to cardiac pressure overload.
  • Determine the impact of genetic alpha2-adrenoceptor variants in human heart failure patients.

Main Methods:

  • Utilized gene-targeted mice lacking specific alpha2-adrenoceptor subtypes (alpha2-KO).
  • Induced chronic left ventricular pressure overload via transverse aortic constriction.
  • Analyzed survival rates, cardiac hypertrophy, fibrosis, and circulating catecholamines in KO and wild-type mice.
  • Assessed clinical status and cardiac function in human heart failure patients with genetic alpha2C-adrenoceptor variants.

Main Results:

  • Survival was significantly reduced in alpha2A-KO and alpha2C-KO mice compared to controls.
  • Alpha2A- and alpha2C-KO mice exhibited exacerbated heart failure, including left ventricular hypertrophy, fibrosis, and elevated catecholamines.
  • Human heart failure patients with dysfunctional alpha2C-adrenoceptor variants showed poorer clinical status and reduced cardiac function.

Conclusions:

  • Alpha2A- and Alpha2C-adrenoceptors play a vital role in preventing heart failure progression.
  • Genetic variants of alpha2-adrenoceptors are associated with worse outcomes in heart failure.
  • Targeting alpha2-adrenoceptor variants and developing subtype-selective drugs offer novel therapeutic strategies for heart failure.

More Related Videos

Implantation of an Isoproterenol Mini-Pump to Induce Heart Failure in Mice05:08

Implantation of an Isoproterenol Mini-Pump to Induce Heart Failure in Mice

Published on: October 3, 2019

A Pacing-Controlled Procedure for the Assessment of Heart Rate-Dependent Diastolic Functions in Murine Heart Failure Models07:49

A Pacing-Controlled Procedure for the Assessment of Heart Rate-Dependent Diastolic Functions in Murine Heart Failure Models

Published on: July 21, 2023

Related Concept Videos

Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers01:24

Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which indirectly block calcium...
Heart Failure Drugs: Diuretics01:22

Heart 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...
Heart Failure Drugs: Inhibitors of Renin-Angiotensin System01:26

Heart 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...
Heart Failure Drugs: β-Blockers01:22

Heart 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...
Heart Failure II: Pathophysiology01:29

Heart 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...
Heart Failure V: Medical Management01:30

Heart 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...