Isolation of high-molecular-weight C-type natriuretic peptide from the heart of a cartilaginous fish (European dogfish, Scyliorhinus canicula).

A high-molecular-weight form of C-type natriuretic peptide (CNP) was isolated from both cardiac atria and ventricles of European dogfish, Scyliorhinus canicula, and its primary structure was determined. The peptide consists of 115 amino acid residues, in which the C-terminal 22 residues show high homology to CNPs identified to date. This is the first direct evidence for the presence of natriuretic peptide in the cartilaginous fish, and for the presence of CNP in an organ other than the brain.