title: Effects of arginine vasopressin and extracellular osmolarity on atrial natriuretic peptide release by superfused rat atria.
abstract: This study investigated the characteristics of atrial natriuretic peptide (ANP) release from superfused sliced atria and ventricles of rats. Right atria spontaneously released more immunoreactive ANP (Ir-ANP: pg/min per mg tissue) (32 +/- 3) than did left atria (11 +/- 2) or right ventricles (1.5 +/- 0.5). Addition of 10(-9) to 10(-5) M of arginine vasopressin (AVP) to the superfusing fluid or increasing its osmolarity (290 to 490 mOsM) resulted in a significant increase of the Ir-ANP outflow from right atria. The effect of AVP was prevented by a specific V1 receptor antagonist, ([d(ch2)5Tyr(Me)]AVP). Superfusion with indomethacin (10(-5) M) did not alter spontaneous release but inhibited the peak levels of Ir-ANP induced by AVP (10(-5) M). Moreover, DDAVP, a specific V2 receptor agonist, did not induce Ir-ANP release. Ca(2+)-free medium alone or plus 1 mM EGTA induced a significant increase in basal Ir-ANP outflow. The Ir-ANP released chromatographed similarly to the standard alpha-rANP. These results suggest a specific stimulatory effect of AVP and osmolarity and a negative influence of extracellular Ca2+ on atrial spontaneous Ir-ANP release. It appears that the effect of AVP could be mediated by prostaglandin synthesis.
authors.affiliation: Service de Biochimie Médicale, Faculté de Médecine, Pitié-Salpêtriere, Paris, France.
authors.forename: M A
authors.initials: MA
authors.lastname: Zongazo
authors.forename: A
authors.initials: A
authors.lastname: Carayon
authors.forename: F
authors.initials: F
authors.lastname: Masson
authors.forename: G
authors.initials: G
authors.lastname: Maistre
authors.forename: E
authors.initials: E
authors.lastname: Noé
authors.forename: J
authors.initials: J
authors.lastname: Eurin
authors.forename: C
authors.initials: C
authors.lastname: Barthelemy
authors.forename: M
authors.initials: M
authors.lastname: Komajda
authors.forename: J C
authors.initials: JC
authors.lastname: Legrand
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D016275:Atrial Function; D016280:Atrial Function, Right / Q000187:drug effects; D009320:Atrial Natriuretic Factor / Q000276:immunology / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006325:Heart Atria / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009994:Osmolar Concentration; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D016276:Ventricular Function
chemical_list: D015220:Calcium Channels; D001127:Arginine Vasopressin; D011189:Potassium Chloride; D009320:Atrial Natriuretic Factor; D002118:Calcium