Differences in the effects of C-type natriuretic peptide on vascular fibrosis, inflammation and remodeling in normotensive and hypertensive rats

CANIFFI, CAROLINA; SUEIRO, LAURA; BOUCHET, GONZALO; ROMERO, MARIANA; TOBLLI, JORGE; ARRANZ, CRISTINA; COSTA, ANGLES

Foz de Iguazú

Congreso; 1st PanAmerican Congress of Physiological Sciences; 2014

Previously, we showed that C-type natriuretic peptide (CNP) acute infusion, increases endothelial nitric oxide synthase activity in both normotensive and spontaneously hypertensive rats (SHR) Aim: to evaluate CNP chronic treatment effects on systolic blood pressure (SBP) and vascular remodeling, fibrosis and inflammation in Wistar (W) and SHR. Methodology: Male W and SHR (12 weeks old) were infused (14 days, osmotic pumps) with CNP (0.75 μg/hora) or saline (S). After chronic treatment, SBP (mmHg) was recorded and rats were sacrificed to perform morphological studies in thoracic aorta sections stained with haematoxylin-eosin (media/lumen ratio, M/L, μm/mm), fibrosis signs with Sirius Red and TGF-β, IL-6 and TNF-α by inmunohistochemistry (stained/total area, %). Values are mean±SEM. Two-way ANOVA, Bonferroni´s posthoc test. Results: In SHR, CNP decreased SBP (W:S=121±3; CNP=120±5; SHR:S=178±3*; CNP=159±5^), fibrosis signs (W:S=10±4; CNP=8±2; SHR:S=34±1*; CNP=19±3^), TGF-β (W:S=1.8±0.6; CNP=1.6±0.5; SHR:S=6.1±1.0*; CNP=2.5±0.4^) and inflammatory cytokines (IL-6: W:S=0.7±0.4; CNP=0.5±0.3; SHR:S=19.2±0.8*; CNP=3.4±0.6^ and TNF-α: W:S=1.4±0.3; CNP=0.9±0.4; SHR:S=18.5±0.9*; CNP=4.4±0.7^) without changes in W. CNP reduced M/L in SHR (W:S=35±9; CNP=37±6; SHR:S=68±11*; CNP=43±7^). n=6rats/group; *p