In vivo left ventricular function and collagen expression in aldosterone/salt-induced hypertension.
Cardiac fibrosis is linked to aldosterone-induced hypertension, but the effects on in vivo left ventricular (LV) function are not established. We studied the relations between in vivo LV function and aldosterone/salt cardiac fibrosis. Adult guinea pigs (GPs) were treated for 3 months with an aldosterone infusion and high-salt diet. This treatment induced arterial hypertension (+35%) and moderate LV hypertrophy (LVH; +60%) without right ventricular (RV) hypertrophy. Echo-Doppler LV assessment demonstrated unaltered cardiac output, stroke volume, or LV relaxation. Type I collagen messenger RNA (mRNA) was significantly increased in both ventricles (LV, +48%; RV, +77%) and accompanied by a significant increase in total collagen deposition (LV, from 0.52% in controls to 4.4% in treated GPs; RV, from 0.82 to 5.5% in treated GPs). Plasma norepinephrine levels increased 2.6-fold (p < 0.01) and correlated with the increase in collagen deposition in both ventricles. Collagen content was not correlated with hypertension or LVH. We conclude that aldosterone administration induces cardiac collagen accumulation and a sympathetic stimulation, which might preserve systolic and diastolic function.
Ramirez-Gil
J F
JF
Laboratoire de Pharmacologie Cardiovasculaire, Institut Federatif de Recherche de Génetique et Physiopathologie Cardiovasculaire INSERM-Hôpital Pitié-Salpêtrière, Hôpital Pitié-Salpêtrière, Paris, France.
Delcayre
C
C
Robert
V
V
Wassef
M
M
Trouve
P
P
Mougenot
N
N
Charlemagne
D
D
Lechat
P
P
D000450:Aldosterone; D000818:Animals; D003094:Collagen / Q000096:biosynthesis* / Q000378:metabolism; D004573:Electrolytes / Q000378:metabolism; D005355:Fibrosis / Q000209:etiology; D006168:Guinea Pigs; D006728:Hormones / Q000097:blood; D006973:Hypertension / Q000139:chemically induced / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D017379:Hypertrophy, Left Ventricular; D017380:Hypertrophy, Right Ventricular; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012492:Salts; D016277:Ventricular Function, Left
D004573:Electrolytes; D006728:Hormones; D012333:RNA, Messenger; D012492:Salts; D000450:Aldosterone; D003094:Collagen