Relevance of the interaction between atrial natriuretic peptide and nitric oxide system in a model of spontaneous hypertension.

CANIFFI CAROLINA; ELESGARAY ROSANA; MAC LAUGHLIN MYRIAM; VISINTINI JAIME MARIA FLORENCIA; FINELLA SEBASTIÁN; BALASZCZUK ANA MARÍA; ARRANZ CRISTINA; COSTA MARÍA DE LOS ÁNGELES

Miami

Congreso; XVIIth Scientific Sessions of the Inter-American Society of Hypertension and the Consortium for Southeastern Hypertension Control.; 2007

Inter-American Society of Hypertension

Atrial natriuretic peptide(ANP) and nitric oxide(NO)induce diuresis, natriuresis and diminish vascular tone. We showed NO-system is involved in ANP hypotensive effect in normotensive rats. The objective was to study changes in systolic blood pressure(SBP) and NO-system induced by ANP in adult spontaneously hypertensive rats(SHR)and the role of the inducible NO synthase (iNOS). Methods: Protocol I: SHR and Wistar Kyoto rats(WKY) divided into two groups were infused with saline(Control,C, 1hour, 0.05ml/min) or ANP (1hour,0.2μg/Kg.min). SBP (mmHg)was recorded and urine samples were recollected for nitrites and nitrates(NOx,nmol/min.100g) determination. NOS activity was measured in aorta and heart. Protocol II: Aorta, right atria and left ventricle (Ventr)from SHR were removed for determination of NOS catalytic activity(pmol L-[U14C]-citrulline/g tissue.min) after addition of: ANP(1μM), cANP(4-23)(NPR-C agonist,1μM)or aminoguanidine(AG,iNOS inhibitor,1μM). Results: Protocol I: ANP diminished SBP in SHR (C:198±4,ANP:165±7^;^p