INFLUENCE OF ATRIAL-NATRIURETIC-PEPTIDE ON CYCLIC-NUCLEOTIDES AND AMYLASE RELEASE IN RAT PAROTID SALIVARY-GLAND IN-VITRO

Atrial natriuretic peptide (ANP), sodium nitroprusside and hydroxylami ne increased cGMP accumulation in rat parotid acinar cells both in the presence and absence of forskolin but in a different manner. On the o ther hand, ANP decreased forskolin-stimulated cAMP accumulation, altho ugh sodium nitroprusside and hydroxylamine had no effect on cAMP accum ulation. Amylase release stimulated by forskolin, dibutyryl-cAMP or is oproterenol was depressed by ANP, whereas sodium nitroprusside and hyd roxylamine did not evoke the inhibition of forskolin-stimulated amylas e release. These results suggest that the inhibition of cAMP accumulat ion and of amylase release by ANP were not mediated via cGMP produced by guanylate cyclase-A.