Natriuretic peptides: potential modulators of circulatory, renal, respiratory, digestive, endocrine, and central nerve systems and implications of their role in bone remodeling

The present paper provides a general review of the biophysiology of natriuretic peptides (NPs) in mammals. NPs, classified as hypotensive hormones, include atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP), as well as their receptors, which involve natriuretic and diuretic activity and also blood circulation and volume homeostasis. This review also summarizes the historical background of NP families and cyclic guanosine monophosphate (cGMP)-dependent protein kinase (cGK1) and their biological properties in cardiovascular tissues, heart diseases, renal functions and disease, respiratory and lung failure, gastrointestinal tissue, urogenital and reproductive organs, endocrine activities, the central nerve system, and bone tissue. ANP triggers natriuretic and diuretic activities in the kidney and alters the electrolyte balance via intestinal absorption of water and sodium ions. CNP is involved in promoting wound healing in arterial endothelial cells. The CNPR-related bone pathway plays a causal active role in bone anomalies, and is a regulator of longitudinal skeletal growth diseases such as achondroplasia. CNP-natriuretic receptor B (CNP/NPR-B) system has signifi cant role in the processes of enchondral ossification. Recently, osteocrin/musclin was discovered as belonging to the NP family; it binds with high affinity to NPR-C and plays a role in bone growth.