title: Interaction between brain natriuretic peptide and atrial natriuretic peptide in caecal circular smooth muscle cells.
abstract: Guinea pig caecal circular smooth muscle cells were used to determine whether brain natriuretic peptide (BNP) can inhibit the contractile response produced by cholecystokinin-octapeptide (CCK-8). In addition, we examined the effect of an inhibitor of cAMP-dependent protein kinase, an inhibitor of particulate or soluble guanylate cyclase, an atrial natriuretic peptide (ANP) antagonist (ANP 1-11), and selective receptor protection on the BNP-induced relaxation of these muscle cells. The effect of BNP on cAMP formation was also examined. BNP inhibited the contractile response produced by CCK-8 in a dose-response manner, with an IC50 value of 8.5 nM, and stimulated the production of cAMP. The inhibitor of cAMP-dependent protein kinase and the inhibitor of soluble guanylate cyclase significantly inhibited the relaxation produced by BNP. In contrast, the inhibitor of particulate guanylate cyclase did not have any significant effect on the relaxation produced by BNP. ANP 1-11 significantly but partially inhibited the relaxation produced by BNP. The muscle cells where CCK-8 and ANP binding sites were protected completely preserved the inhibitory response to ANP, but partially preserved the inhibitory response to BNP. The muscle cells where CCK-8 and BNP binding sites were protected completely preserved the inhibitory response to both ANP and BNP. This study demonstrates that BNP induces relaxation of these muscle cells via both ANP binding sites coupled to soluble guanylate cyclase and distinct BNP binding sites coupled to adenylate cyclase.
authors.affiliation: Department of Clinical Genetics, Medical Institute of Bioregulation, Kyushu University, Beppu, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Yasuda
authors.forename: Y
authors.initials: Y
authors.lastname: Chijiiwa
authors.forename: Y
authors.initials: Y
authors.lastname: Motomura
authors.forename: T
authors.initials: T
authors.lastname: Ochiai
authors.forename: H
authors.initials: H
authors.lastname: Nawata
mesh_terms: D000634:Aminoquinolines / Q000494:pharmacology; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D001665:Binding Sites; D002432:Cecum / Q000187:drug effects; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D006168:Guinea Pigs; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects*; D020097:Natriuretic Peptide, Brain / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D012844:Sincalide / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology
chemical_list: D000634:Aminoquinolines; D010446:Peptide Fragments; D013873:Thionucleotides; D020097:Natriuretic Peptide, Brain; C016957:adenosine-3',5'-cyclic phosphorothioate; D009320:Atrial Natriuretic Factor; C041715:6-anilino-5,8-quinolinedione; C058130:atrial natriuretic factor (1-11); D000242:Cyclic AMP; D012844:Sincalide; D013755:Tetradecanoylphorbol Acetate