CHARACTERIZATION OF NATRIURETIC PEPTIDE RECEPTORS IN THE RAT PAROTID

Competition studies between I-125-ANP and ANP (atrial natriuretic pept ide) or the ring-deleted analog C-ANF(4-23) (C-ANF) revealed the prese nce of the A-type natriuretic peptide receptor (GC-A receptor) and the ANP-clearance (ANP-C) receptor in the rat parotid membrane. The ratio of the GC-A and ANP-C receptors was about 3 to 1. Enhancement of the cGMP level by the C-type natriuretic peptide (CNP) revealed the presen ce of the B-type natriuretic peptide receptor (GC-B receptor) in the r at parotid gland. Based on the binding studies with ANP and C-ANF and cGMP analysis by ANP and CNP, the natriuretic peptide receptors in the rat parotid gland were demonstrated to have a rank order on the amoun t of GC-A receptor > GC-B receptor > ANP-C receptor.