Natriuretic Peptide System in the Brain and Its Implication in Central Cardiovascular Regulation

Atrial natriuretic peptide (ANP) is a peptide hormone first isolated from the cardiac atrium and it possesses potent diuretic, natriuretic, and vasorelaxant activities (De Bold, 1985). The discovery of ANP cast light on the heart as an endocrine organ involved in the control of blood pressure and body fluid homeostasis (Cantin and Genest, 1985; Kangawa et al., 1984; Needleman et al., 1985). Soon after the discovery of this peptide in the heart, investigations using radioimmunoassay (RIA) and immunohistochemistry revealed the existence of ANP in the central nervous system (CNS), and suggested the involvement of this peptide in the central regulation of cardiovascular homeostasis as a neurotransmitter or neuromodulation (Imura and Nakao, 1990; Nakao et al., 1986b; Quirion, 1988; Samson, 1987; Saper et al., 1985).