Effects of a selective beta 2-blocker (ICI 118,551) on hepatic haemodynamics in the cirrhotic and non-cirrhotic rat.

The effects of a selective beta 2-blocker (ICI 118,551) on hepatic haemodynamics were studied in cirrhotic and non-cirrhotic rats. Infusions of 10 and 20 microgram (kg body wt)-1 min-1 beta 2-blocker (in cirrhotic and non-cirrhotic rats) significantly reduced portal pressure, portal venous flow and liver blood flow without altering heart rate. Splanchnic vascular resistance was significantly increased following infusions of 10 and 20 micrograms (kg body wt)-1 min-1 beta 2-blocker. An intraportal injection of beta 2-blocker (10 micrograms body wt)-1 or hepatic artery ligation lowered portal pressure by approximately the same magnitude. Intraportal injection of beta 2-blocker after hepatic artery ligation did not further reduce portal pressure. The results indicate that a selective beta 2-blocker reduces portal pressure by a combination of increased splanchnic vascular resistance and hepatic arterial resistance. It is concluded that a selective beta 2-blocker may be of clinical value in the long-term managements of portal hypertension.