Sex difference in vascular response to atrial natriuretic peptide in spontaneously hypertensive rats

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

Jackson, Mississippi

Congreso; Physiology of Cardiovascular Diseases: Gender Disparities; 2011

American Physiological Society

The aim was to investigate vascular effects of chronic infusion with atrial natriuretic peptide (ANP) in spontaneously hypertensive rats (SHR), look for sex differences. Methods: 10 weeks-old male (M) and female (F) SHR were infused (14 days, osmotic pumps) with ANP (100 ng/hr.rat) or saline (S).Systolic blood pressure (SBP,mmHg) and nitrites and nitrates excretion (NOx,nmol/min.100g) were determined. Animals were sacrificed to perform morphological studies in thoracic aorta sections stained with haematoxylin-eosin (media/lumen ratio, m/mm) and fibrosis signs with Sirius Red and Masson´sTrichromic (Score). Aortic NOS activity (14C L-arginine, pmol/g.tissue.min) was determined. Cardiac ventricle and kidney sections were stained with Sirius Red, to evaluate perivascular collagen in coronary and renal arteries. Results: Aorta SBP NOx NOS activity Media/Lumen Trichromic Sirius Red M S 183±4 2.4±0.2 264±8 74.1±2.3 3.76±0.14 3.25±0.21 M ANP 171±4* 3.6±0.3* 353±6* 65.7±1.9* 3.26±0.19 3.05±0.13* F SF 170±3* 3.2±0.2* 301±4* 65.6±2.5* 2.47±0.14* 2.75±0.38* F ANP 162±3# 4.3±0.4# 410±3# 62.9±3.6 2.55±0.28 1.50±0.35# *p< 0,01 vs M S; #p