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 MARIA DE LOS ANGELES

Jackson, Mississippi

Congreso; 2011 APS Conference: Physiology of cardiovascular disease: gender disparities.; 2011

American Phsyiological 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, mm/mm) and fibrosis signs with Sirius Red (ASR) (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 (CA) and renal arteries (RA) (µm/mm lumen). Results: SBP NOx NOS Aorta ASR RA CA M S 183±4 2.4±0.2 264±8 74.1±2.3 3.2±0.2 11.8±0.7 8.4±1.2 M ANP 171±4* 3.6±0.3* 353±6* 65.7±1.9* 3.1±0.1* 7.5±1.1* 3.5±0.4* F S 170±3* 3.2±0.2* 301±4* 65.6±2.5* 2.7±0.4* 11.6±1.5* 3.4±0.1* F ANP 162±3# 4.3±0.4# 410±3# 62.9±3.6 1.5±0.3# 6.6±1.1# 1.9±0.4# *p< 0,01 vs M S; #p<0,01 vs F S. Two-way ANOVA followed by Bonferroni´s post-hoc test. In coronary and renal arteries, perivascular collagen area was higher in M than in F SHR and ANP reduced this parameter in both sex. Conclusions: ANP treatment increased vascular NO system, improving aortic wall properties and modifying coronary and renal arteries remodelling in SHR.