Alpha-atrial natriuretic peptide binding sites in the rat choroid plexus are increased in the presence of hydrocephalus.

Specific alpha-rat atrial natriuretic peptide(1-28) [ANF-(99-126)] (rANP) binding sites in the choroid plexus of rats with kaolin-induced hydrocephalus were analyzed following incubation of related tissue sections with 125I-rANP, then using autoradiography and an image analysis coupled with computer-assisted micro-densitometry. The number of 125I-rANP binding sites in the choroid plexus of these rats 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. The possibility that atrial natriuretic peptide may play a significant role in the function of cerebrospinal fluid production by interacting with specific, high affinity receptors in the rat choroid plexus has to be considered.