AJP - Gastrointestinal and Liver Physiology, Vol 257, Issue 1 52-G57, Copyright © 1989 by American Physiological Society
Portal venous pressure and portasystemic shunting in experimental portal hypertension
J. G. Geraghty, W. J. Angerson and D. C. Carter
University Department of Surgery, Royal Infirmary, Glasgow, United Kingdom.
The relationship between portal venous pressure and the degree of
portasystemic shunting was studied in portal vein-ligated and cirrhotic
rats anesthetized with halothane. One day after partial portal vein
ligation there was a strong positive correlation (r = 0.80, n = 7) between
portal pressure and shunting of mesenteric venous blood as measured by
injection of radioactive microspheres. The relationship subsequently
underwent rapid change but stabilized by 14 days postligation, when higher
levels of shunting were again associated with higher portal pressures up to
a limit of approximately 70% shunting, above which pressures did not
increase further. This relationship was well described by a quadratic
function (r = 0.75, n = 17). In cirrhotic rats there was no relationship
between portal pressure and shunting (r = -0.01, n = 10). The results
suggest that in the prehepatic model there is little inherent variability
in capacity to develop shunts, which open to a degree directly related to
portal pressure, but that this relationship may be altered in cirrhotic
portal hypertension.
