Korean J Gastroenterol.  2000 Jan;35(1):54-63.

Effects of Nitric Oxide Inhibitor on Hyperdynamic Circulation in a Portal Vein-Stenosed Rat Model

• Jang BI
• Kim TN
• Chung MK

Abstract

BACKGROUND/AIMS
The present study investigated effects of nitric oxide on hyperdynamic circulation associated with peripheral vasodilation in partial portal vein ligated rat. METHODS: Portal hypertensive rats were divided into 3 groups. Group 1 received an intravenous bolus injection of saline. Group 2 received N -Nitro-L-Arginine (NNA) and group 3 was administrated with L-arginine 5 min before administration of NNA. Systemic and hepatic hemodynamics were measured by radioisotope labeled microsphere method and vascular resistance was calculated by standard equation. RESULTS: In group 1, mean arterial pressure was significantly decreased, compared with controls, and cardiae output and splanchnic vasodilation were increased (p<0.01). On the other hend, in group 2, mean arterial pressure was significantly increased, and cardiac output was decreased. Moreover, splanchnic vascular resistance (p<0.05) of this group was higher than that of controls despite of no change in portal pressure (p>0.05). Such changes by NNA in group 2 were blocked by prior adminstration of L-arginine (p<0.05) in group 3. CONCLUSIONS: These findings indicate that the chronic portal hyperdynamic circulatory characteristics can be attenuated by NNA. Thus, nitric oxide may be implicated in the pathogenesis of hemodynamic disturbances and splanchnic vasodilation associated with chronic portal hypertension.

Keyword

Portal hypertension; Hyperdynamic circulation; Nitric oxide

MeSH Terms

Animals
Arginine
Arterial Pressure
Cardia
Cardiac Output
Hemodynamics
Hypertension, Portal
Microspheres
Models, Animal*
Nitric Oxide*
Portal Pressure
Portal Vein
Rats*
Vascular Resistance
Vasodilation
Arginine
Nitric Oxide