Ventricular function and natriuretic peptides in sequentially combined models of hypertension.
Hemodynamic parameters and natriuretic peptide levels were evaluated in cardiac hypertrophy produced by sequentially applied renovascular (RV) and deoxycorticosterone acetate-salt (DS) models of hypertension. We studied hypertensive rats by RV or DS treatment at 2 and 4 wk, as well as by the combination of 2 wk of each treatment in an inverse sequence: RV 2 wk/DS 2 wk (RV2/DS2) and DS 2 wk/RV 2 wk (DS2/RV2). The in vivo cardiac function, interstitial fibrosis, and synthesis and secretion of types A (ANP) and B (BNP) natriuretic peptides were monitored in hypertensive models compared with their corresponding sham (Sh2, Sh4). There were no differences in relaxation parameters among RV or DS groups and combined treatments. Left ventricular +dP/dt(max) increased only in RV4 (P < 0.01 vs. Sh4), and this increase was abolished in RV2/DS2. Interstitial collagen concentration increased after 4 wk in both RV4 and RV2/DS2 groups. Although there were no changes in collagen concentration in either DS2 or DS4 groups, clipping after 2 wk of DS (DS2/RV2) remarkably stimulated interstitial fibrosis (P < 0.01 vs. DS2). Plasma BNP increased in RV treatment at 4 wk (P < 0.001 vs. Sh4), but not in DS. Interestingly, RV applied after the 2 wk of DS treatment induced a marked increase in BNP levels (P < 0.001 vs. Sh4). In this regard, plasma BNP appears to be a reliable indicator of pressure overload. Our results suggest that the second stimulus of mechanical overload in combined models of hypertension determines the evolution of hypertrophy and synthesis and secretion of ANP and BNP.
Department of Pathophysiology, Institute of Pathophysiology and Clinical Biochemistry, University of Buenos Aires, Argentina. susanac@ffyb.uba.ar
Susana
S
Cavallero
Germán E
GE
González
Ignacio M
IM
Seropian
Carolina S
CS
Cerrudo
Federico
F
Matorra
Celina
C
Morales
Cecilia M
CM
Hertig
Ana M
AM
Puyó
Belisario E
BE
Fernández
Ricardo J
RJ
Gelpi
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D001696:Biomechanical Phenomena; D001794:Blood Pressure / Q000502:physiology; D003094:Collagen / Q000378:metabolism; D003900:Desoxycorticosterone / Q000009:adverse effects / Q000031:analogs & derivatives; D004195:Disease Models, Animal; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology*; D006978:Hypertension, Renovascular / Q000378:metabolism* / Q000503:physiopathology*; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000378:metabolism; D045265:Natriuretic Peptides / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016277:Ventricular Function, Left / Q000502:physiology*
D045265:Natriuretic Peptides; D020097:Natriuretic Peptide, Brain; D003900:Desoxycorticosterone; D009320:Atrial Natriuretic Factor; D003094:Collagen