Alteration of atrial natriuretic peptide receptors in the choroid plexus of rats with induced or congenital hydrocephalus.

Specific binding sites for atrial natriuretic peptide (ANP) in the choroid plexus of rats with induced or congenital hydrocephalus were examined using in vitro quantitative receptor autoradiographic methods. The number of 125I-ANP binding sites in the choroid plexus of rats with kaolin-induced hydrocephalus was significantly higher as compared to findings in the control rats, whereas no differences in the binding affinity were observed 3 days and 3 weeks after the intracisternal injection of kaolin. Conversely, rats with congenital hydrocephalus (LEW-HYR and HTX rats) had a small number of binding sites for 125I-ANP in the choroid plexus, as compared to findings in the control rats. These alterations may relate to the pathophysiology of hydrocephalus. The possibility that atrial natriuretic peptide may be involved in the regulation of cerebrospinal fluid production in the choroid plexus must be considered.