Biochemistry of a Natriuretic Peptide Family

Abstract

It was 8 years ago, when ANP (atrial/A-type natriuretic peptide) was first identified in mammalian heart. The peptide elicits vasorelaxant, diuretic and natriuretic activities. Furthermore, ANP is known to be secreted from the heart, circulates in the blood and participates in the regulation of salts-water balance and blood pressure. These facts revealed that the heart is not only a mechanical pump impelling blood, but is also an endocrine organ regulating the circulation system. Thus, the peptide represents an exciting and hopeful new direction in the circulation research. Identification of ANP induced an explosive series of investigations in the related fields. However, there is much more to be learned for understanding the still puzzling significance of the peptide. Subsequent to the discovery of ANP, another natriuretic peptide designated BNP (brain/B-type natriuretic peptide), was isolated from porcine brain (Sudoh et al., 1988). BNP is very similar to ANP structurally as well as pharmacologically.