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The negative inotropic action of catecholamines: role of beta3-adrenoceptors
C Gauthier1, V Leblais, S Moniotte
1Laboratoire de Physiopathologie et Pharmacologie Cellulaires et Moléculaires, INSERM U533, Nantes, France. chantal.gauthier@nantes.inserm.fr
Abstract:
There is now evidence for the involvement of four beta-adrenoceptor populations in the regulation of cardiac function by catecholamines. Beta1- and beta2-adrenoceptor stimulation classically produces an increase in contractility. A fourth beta-adrenoceptor, as yet uncloned and designated provisionally as a beta4-adrenoceptor, also mediates a positive inotropic effect. Beta3-adrenoceptors, which had been cloned at the end of the eighties, has been extensively studied as a potential target for antiobesity and antidiabetic drugs. Its characterization in the heart has opened new fields of investigations for the understanding of the cardiac adrenergic regulation. This review describes the cardiac electrical and mechanical effects induced by Beta3-adrenoceptor stimulation in different species (including human), as well as the signaling pathway. It also analyzes the role of these receptors in the abnormal responsiveness of catecholamines in heart failure.
Insights
This review explores beta3-adrenoceptors in the heart, detailing their electrical and mechanical effects and signaling pathways. It examines their role in catecholamine response, particularly in heart failure.
Area of Science:
- Cardiology
- Pharmacology
- Molecular Biology
Background:
- Catecholamines regulate cardiac function via four beta-adrenoceptor populations.
- Beta1 and beta2-adrenoceptor stimulation increases cardiac contractility.
- A provisional beta4-adrenoceptor also mediates positive inotropic effects.
Purpose of the Study:
- To review the cardiac electrical and mechanical effects of beta3-adrenoceptor stimulation.
- To elucidate the signaling pathways involved in beta3-adrenoceptor activation.
- To analyze the role of beta3-adrenoceptors in altered catecholamine responsiveness in heart failure.
Main Methods:
- Literature review of studies on beta3-adrenoceptor function in cardiac tissue.
- Analysis of signaling pathways downstream of beta3-adrenoceptor activation.
- Examination of beta3-adrenoceptor involvement in various species, including humans.
Main Results:
- Beta3-adrenoceptors, cloned in the late 1980s, are potential targets for metabolic disorders.
- Characterization in the heart reveals new insights into cardiac adrenergic regulation.
- Beta3-adrenoceptor stimulation induces specific electrical and mechanical effects in the heart.
Conclusions:
- Beta3-adrenoceptors play a significant role in cardiac adrenergic regulation.
- Understanding beta3-adrenoceptors opens new avenues for cardiac research.
- These receptors are implicated in the pathophysiology of heart failure.