The role of natriuretic peptides in cardiovascular disorders and human cardiac allografts (Review).
The human myocardium is composed of a variety of cardiac cell types that synthesise cardioactive factors with autocrine, paracrine and endocrine functions. These cardioactive factors include a family of structurally and functionally related peptides, natriuretic peptides (NPs), that act as cardiovascular cell growth modulatory factors and have significant influence on the regulation of cardiovascular function. The three members of the NP family are atrial natriuretic peptide, brain natriuretic peptide and C-type natriuretic peptide. NPs are ubiquitously expressed in cardiovascular tissues and have specific receptors in cardiac cells, brain cells, vascular endothelial cells and extracardiac tissues through which they elicit a variety of biological responses including natriuresis, diuresis and vasodilation. Cardiac transplantation is the most effective and definitive treatment for end-stage cardiac failure in humans. Orthotopic cardiac transplantation and cardiovascular disorders including hypertension, cardiac hypertrophy, cardiac failure, result in increased myocardial expression of NPs, suggesting a pathophysiological role for these peptides in the heart. The mechanism by which the expression of NPs is regulated in the transplanted human heart is not well understood. Understanding the mechanism of local expression of NPs and their interactions with other putative growth regulatory factors in the human heart may have important implications for potential management of cardiovascular disorders and cardiac transplantation. This article will discuss the current knowledge of NPs in cardiovascular disorders. Most of the emphasis will focus on their possible role in human cardiac allografts as there have been no reviews on this important topic.