HIGHER PROPORTIONS OF TYPE-C THAN OF TYPE-A AND TYPE-B NATRIURETIC PEPTIDE RECEPTORS EXIST IN THE RAT CILIARY BODY

We investigate the interaction of atrial natriuretic peptide (ANP), br ain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) wit h their receptors (NPRA, NPRB and NPRC), as well as the proportion and localization of those receptors in the rat ciliary body. Binding assa ys and affinity cross-linking experiments demonstrated the presence of the NPRC receptor type. However, the three natriuretic peptides stimu late the guanylate cyclase activity in the ciliary body membranes sugg esting the presence of the NPRA and NPRB receptor type. Microautoradio graphic data show that the NPRs are localized in the whole ciliary bod y. Our results indicated that NPRC is the most prominent receptor type in this tissue. (C) 1998 Elsevier Science Ltd. All rights reserved.