title: Direct vasodilatory action of atrial natriuretic factor on canine glomerular afferent arterioles.
abstract: Studies were performed to examine whether atrial natriuretic peptide (ANP) has a direct action on glomerular afferent arterioles, and if so, whether the action is mediated by guanosine 5'-cyclic monophosphate (cGMP). A single superficial afferent arteriole was dissected from the canine kidney and perfused with the single glomerular perfusion technique described by Osgood et al. [Am. J. Physiol. 244 (Renal Fluid Electrolyte Physiol. 13): F349-F354, 1983]. Norepinephrine (NE, 1 x 10(-6) M) significantly increased arteriolar resistance, calculated from the perfusion rate and arteriolar pressure. Synthetic human ANP (hANP) provoked afferent arteriolar dilation and attenuated the NE-induced increase in arteriolar resistance with 1 x 10(-10) to 1 x 10(-6) M concentrations. This vasodilatory effect was significantly potentiated by 2-o-propoxyphenyl-8-azapurin-6-one (M&B 22,948, 4 x 10(-12) M), a cGMP phosphodiesterase inhibitor, probably due to a sequential interaction of synergistic drugs. Also, the 1 x 10(-4) M concentration of 8-bromoguanosine 5'-cyclic monophosphate or dibutyryl guanosine, 5'-cyclic monophosphate (DBcGMP) lessened NE-induced arteriolar constriction, but DBcAMP did not. We conclude from these observations that ANP has a direct vasodilatory action on canine glomerular afferent arterioles, and that this ANP-induced vasodilation is mediated by enhanced cGMP synthesis.
authors.affiliation: First Department of Medicine, Hamamatsu University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ohishi
authors.forename: A
authors.initials: A
authors.lastname: Hishida
authors.forename: N
authors.initials: N
authors.lastname: Honda
mesh_terms: D000818:Animals; D001158:Arteries / Q000502:physiology*; D001160:Arterioles / Q000187:drug effects / Q000502:physiology*; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007678:Kidney Glomerulus / Q000098:blood supply*; D009638:Norepinephrine / Q000494:pharmacology; D011688:Purinones / Q000494:pharmacology; D014655:Vascular Resistance / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation
chemical_list: D011688:Purinones; D009320:Atrial Natriuretic Factor; C011145:zaprinast; D009638:Norepinephrine