Systemic vasoconstriction induced by inhibition of nitric oxide synthesis is attenuated in conscious dogs with heart failure.
OBJECTIVE
The aim was to test the hypothesis that endothelium dependent vasomotor control is impaired in heart failure.


METHODS
The haemodynamic effects of NG-nitro-L-arginine (NNA), an inhibitor of nitric oxide synthesis, were studied in five dogs with and without pacing induced heart failure.


RESULTS
In healthy dogs, NNA increased total peripheral resistance and arterial pressure, decreasing cardiac output and heart rate. These effects were partially reversed by L-arginine. In dogs with heart failure, NNA did not change any haemodynamic variable. However, L-arginine decreased total peripheral resistance.


CONCLUSIONS
These findings support a physiological role for endothelium derived nitric oxide in control of vascular resistance and are in agreement with the hypothesis that endothelium dependent vasomotion may be impaired in heart failure.
Elsner
D
D
Medizinische Universitätsklinik, Würzburg, Germany.
Müntze
A
A
Kromer
E P
EP
Riegger
G A
GA
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D002304:Cardiac Pacing, Artificial; D004285:Dogs; D004730:Endothelium, Vascular / Q000503:physiopathology; D006333:Heart Failure / Q000209:etiology / Q000503:physiopathology*; D006439:Hemodynamics / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism*; D019335:Nitroarginine; D014661:Vasoconstriction / Q000502:physiology*
D019335:Nitroarginine; D009569:Nitric Oxide; D001120:Arginine