Vascular response to atrial natriuretic peptide chronic treatment in hypertension.

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

Milán, Italia

Congreso; 21st European Meeting on Hypertension and Cardiovascular Prevention; 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 of spontaneous 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) were determined during the experimental period. The animals were sacrificed to perform morphological studies in thoracic aorta sections stained by haematoxylin-eosin (intima thickness, µm; media thickness, µm) and to determine fibrosis signs with picrosirius red and Masson´sTrichromic. Aortic NOS activity (14C L-arginine, pmol/g.tissue.min) was also determined. Cardiac ventricle and kidney sections were stained by picrosirius red to evaluate perivascular collagen (collagen area/lumen area) in coronary and renal arteries. In coronary and renal arteries, perivascular collagen area was higher in male than in female SHR and ANP treatment reduced this parameter in both gender. Conclusion: Vascular NO system activity in F SHR is more activated than M. ANP treatment reduced endothelial dysfunction and target organ damage in both sexes.