Phospholipase C signaling tonically represses basal atrial natriuretic factor secretion from the atria of the heart.

The cardiac hormone atrial natriuretic factor (ANF or ANP) plays significant, well-established roles in a large number of physiological and pathophysiological processes, including water and electrolyte balance, blood pressure regulation, and cardiovascular growth. Understanding the regulation of its production and secretion by atrial cardiomyocytes is incomplete. We have previously established a significant role of G(i/o) protein signaling in modulating ANF secretion as promoted by stretch of the atrial myocardium.

Ras dexamethasone-induced protein 1 is a modulator of hormone secretion in the volume overloaded heart.

Because of the crucial role of the endocrine heart in maintaining homeostasis, considerable effort has been focused on the elucidation of the mechanistic underlying gene expression and secretion of the cardiac hormones atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP). However, much remains to be determined regarding specific molecular events involved in cardiocyte secretory function. In this work, we identified genes involved in the transcriptional response of the endocrine heart to volume overload (VO) and signaling pathways involved in its regulation.

Transcriptional analysis of the mammalian heart with special reference to its endocrine function.

Background: Pharmacological and gene ablation studies have demonstrated the crucial role of the endocrine function of the heart as mediated by the polypeptide hormones ANF and BNP in the maintenance of cardiovascular homeostasis. The importance of these studies lies on the fact that hypertension and chronic congestive heart failure are clinical entities that may be regarded as states of relative deficiency of ANF and BNP. These hormones are produced by the atrial muscle cells (cardiocytes), which display a dual secretory/muscle phenotype.

The endocrine function of the heart.

Atrial cardiocytes in the heart of mammals produce in a regulated manner the polypeptide hormones atrial natriuretic factor (ANF, ANP) and brain natriuretic peptide (BNP). The biological actions of ANF and BNP are similar; they include the modulation of systems that tend to increase extracellular fluid volume and blood pressure, such as the renin-angiotensin system and the sympathetic nervous system. Additionally, both hormones have potent growth-regulating properties.

Determinants of natriuretic peptide gene expression.

The cardiac natriuretic peptides (NP) atrial natriuretic factor or peptide (ANF or ANP) and brain natriuretic peptide (BNP) are polypeptide hormones synthesized, stored and secreted mainly by cardiac muscle cells (cardiocytes) of the atria of the heart. Both ANF and BNP are co-stored in storage granules referred to as specific atrial granules. The biological properties of NP include modulation of intrinsic renal mechanisms, the sympathetic nervous system, the rennin-angiotensin-aldosterone system (RAAS) and other determinants, of fluid volume, vascular tone and renal function.