C-type natriuretic peptide and cardiovascular nitric oxide system in hypertension.

COSTA MARÍA DE LOS ÁNGELES; CANIFFI CAROLINA; RODRIGUEZ IERASE DANIELA; MARTORELL CARO MIGUEL ANGEL; ELESGARAY ROSANA; ARRANZ CRISTINA

Milán

Congreso; Nineteenth European Meeting of Hypertension.; 2009

European Society of Hypertension.

C-type natriuretic peptide (CNP) plays an important role in cardiovascular homeostasis. In previous studies we demonstrated that CNP increases cardiovascular nitric oxide synthase (NOS) activity. The aim was to investigate changes in mean arterial pressure (MAP) and nitric oxide (NO) system induced by CNP and to elucidate natriuretic receptor and NOS isoform involved in the interaction between the peptide and NO-system in spontaneously hypertensive rats (SHR). Methods: A- In vivo studies: 12-weeks old SHR and normotensive Wistar Kyoto rats (WKY) were intravenously infused with saline (NaCl 0.9%) or CNP (1µg/Kg.min) during 60 minutes. MAP (mmHg) was recorded and nitrites and nitrates in plasma (PNOx, nM) and urine (UNOx, nmol/min.100g) were determined at the end of experimental time. Then animals were sacrifized by decapitation and NOS activity (using [14C] L-arginine as substrate) and endothelial NOS (eNOS) expression (Wsetern Blot) were determined in right atria (RA), left ventricle (LV) and aorta artery (AA). B- In vivo studies: NOS activity induced by CNP addition was determined in presence of: anatin (NPR-A/B receptors blocker), aminoguanidine (inducible NOS inhibitor) or 7-NI (neuronal NOS inhibitor) in heart and aorta of SHR. Results: A- In vivo: *p