Vascular response to atrial natriuretic peptide chronic treatment in hypertension.

COSTA MARÍA DE LOS ÁNGELES; ROMERO MARIANA; BOUCHET GONZALO; SAVIGNANO LUCÍA; CANIFFI CAROLINA; ELESGARAY ROSANA; MAC LAUGHLIN MYRIAM; ARRANZ CRISTINA

Milán

Congreso; 21st European Meeting of Hypertension.; 2011

European Society of Hypertension.

Abundant evidence indicates that high blood pressure is associated to endothelial dysfunction and vascular damage. In previous studies we demonstrated that atrial natriuretic peptide (ANP) increases cardiac and renal nitric oxide synthase (NOS) activity in spontaneously hypertensive rats (SHR). The aim was to investigate vascular effects of chronic infusion with ANP in SHR and to compare this response in male (M) and female (F) rats. Methods: 10 weeks-old M and F SHR were infused (14 days, subcutaneous osmotic pumps) with ANP (100 ng/hr/rat) or saline (S). Systolic blood pressure (SBP, mmHg) was recorded and nitrites and nitrates excretion (NOx, metabolic end products of NO, nmol/min.100g) was determined at the end of the experimental period. The animals were sacrificed to perform morphological studies in thoracic aorta sections stained with haematoxylin-eosin (media thickness, µm; media/lumen ratio, µm/mm) and to determine fibrosis signs with picrosirius red and Masson´sTrichromic (Score). Aortic NOS activity (14C L-arginine, pmol/g.tissue.min) was determined.Cardiac ventricle and kidney sections were stained by picrosirius red to evaluate perivascular collagen in coronary and renal arteries. Results: *p< 0,01 vs M S; #p