[Nitric oxide in pathogenesis of cirrhotic portal hypertension in rats and its hemodynamic effects].
OBJECTIVE
To measure serum nitrite and nitrate levels as an index for in vivo nitric oxide generation in rats at different stages during the development of cirrhosis with portal hypertension.


METHODS
Plasma endotoxin and hemodynamic parameters were measured. The effects of NO-monomethyl-L-arginine (L-NMMA), an inhibitor of NO biosynthesis were investigated in rats with cirrhosis.


RESULTS
Significant increase was noted in serum nitrite/nitrate and plasma endotoxin compared with controls at each stage of cirrhosis. At each stage, the mean arterial pressure (MAP) and splanchnic vascular resistance (SVR) were significantly lower than those of controls, whereas portal venous pressure (PVP) and portal vascular resistance (PVR) significantly increased and portal venous flow (PVF) was not markedly different from that of the controls. In addition, the serum nitrite/nitrate levels significantly were correlated with endotoxemia and PVP. Intravenous bolus administration of L-NMMA (25 mg/kg) significantly increased MAP, PVR and SVR in cirrhotic rats. L-NMMA also significantly decreased PVF but did not alter PVP and IVCP.


CONCLUSIONS
The excessive synthesis and release of NO plays a key role in the induction of portal hypertension.
Zhang
J
J
Department of Surgery, Affiliated Hospital of Guiyang Medical College, Guiyang 550001.
Zhou
H
H
D000818:Animals; D006439:Hemodynamics; D006975:Hypertension, Portal / Q000209:etiology*; D008106:Liver Cirrhosis, Experimental / Q000150:complications*; D008297:Male; D009569:Nitric Oxide / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
D009569:Nitric Oxide