Cerebrospinal fluid concentrations of atrial natriuretic peptide in children.

Concentrations of atrial natriuretic peptide (ANP) in plasma and in cerebrospinal fluid (CSF) were measured in preterm neonates, in infants and in children with hydrocephalus. Plasma ANP in preterm neonates were elevated compared to infants and children with hydrocephalus. CSF-ANP in all groups were lower than plasma levels. ANP concentrations in the liquor exhibited higher values in children with hydrocephalus. No correlation was found between plasma and CSF-ANP levels while CSF-pressure and ANP concentration in the liquor correlated positively. Our data provide evidence for the existence of a cerebral ANP system in humans. The CSF-ANP system seems to be independent from the systemic, atrial ANP. CSF-ANP may be of great importance in the regulation of water and ion content of central nervous system and probably liquor formation.