C-type natriuretic peptide treatment and cardiovascular function in spontaneouly hypertensive rats

COSTA, A; CANIFFI, C; CERNIELLO, M; ROMERO, M; SUEIRO, L; RADIONOVAS, V; ARRANZ, C

Congreso; ? 23 European Meeting on Hypertension and Cardiovascular protection.; 2013

The aim was to evaluate the effects of C-type natriureticpeptide (CNP) on systolic blood pressure (SBP), cardiac and vascular function, and nitric oxide synthase (NOS) activity on cardiac left ventricle (LV) and aorta artery (AA), in spontaneously hypertensive rats (SHR). Methods: 12 weeks-old male SHR were infused (14 days, osmotic pumps) with CNP (0,75 µg/hr.rat) or saline (S). SBP (mmHg) was recorded and echocardiography was performed. Animals were decapitated and NOS activity (pmol 14C L-citrulline/g.tissue. min) was measured in AA and LV. Vascular reactivity in AA was studied, evaluating maximal response to phenylephrine (Rmax) and concentration of acetylcholine (expressed as negative log molar) producing 50% of maximum relaxation (pEC50). Statistics: t-test. SBP 175±3 159±5*Heart rate (bpm) 435±10 434±15End-diastolic volume (ml) 0,16±0,02 0,23±0,03*End-systolic volume (ml) 0,05±0,02 0,07±0,03Stroke volume (ml/min) 0,11±0,01 0,16±0,02*Cardiac output (ml) 47,8±2,0 68,8±7,4*Ejection fraction % 69±6 71±6Fractional shortening % 34±5 35±4NOS LV 255±5 371±8*NOS AA 117±16 202±4*Rmax 1,01±0,16 0,46±0.06*pEC50 7,4±0,1 9,3±0.2*Values are means ± SEM. *p<0.05 vs S; n=6 rats/group.Conclusion: Chronic treatment with CNP decreased blood pressure, activating cardiovascular NOS, improving cardiac efficiency and vascular function, in this model of hypertension. Supported by: UBA-Conicet.S CNP