[Alterations of atrial natriuretic peptide receptor in the choroid plexus of rats with congenital hydrocephalus (LEW-HYR and HTX)].

By using quantitative receptor autoradiography, specific atrial natriuretic peptide (ANP) binding sites in the choroid plexus of congenital hydrocephalic rats (LEW/HYR and HTX strains) were analyzed. The effect of ANP on cyclic GMP production in the choroid plexus of these rats were also examined. The number of 125I-ANP binding sites in the choroid plexus of rats with congenital hydrocephalus (both LEW/HYR and HTX strains) was significantly lower, at 0.3 nM 125I-ANP concentrations, when compared with those in the age-matched control rats. This alteration was specific in the choroid plexus, since no significant difference in the binding of 125I-ANP was observed in the olfactory bulb. On the other hand, in spite of lower number of 125I-ANP binding sites in the choroid plexus, cyclic GMP response to ANP in these rats was similar to that of age-matched control Lewis rats. These results suggest that ANP receptor may play a role in the regulation of cerebrospinal fluid production. Alterations in ANP receptor in the choroid plexus might be involved in the development of congenital hydrocephalus.