The effects of selective and non-selective adrenoceptor blockade on the portal blood flow in patients with liver cirrhosis

The effects of different types of adrenoceptor blocking agents on portal venous blood flow were studied in 10 patients with liver cirrhosis by using a duplex Doppler system. Oral atenolol (selective beta 1 blocker), propranolol (non-selective beta blocker), and labetalol (non-selective adrenoceptor blocker) were compared. The drugs were administered at random at an interval of 3 days or more. Hemodynamic measurements were done before and after 1 h, 2 h, and 3 h of therapy. Atenolol and propranolol produced significant decrease in the portal vein cross-sectional area, portal blood velocity, and estimated volume of the portal blood flow. The portal blood velocity decreased by 13.1 +/- 7.2% 3 h after atenolol and by 16.2 +/- 6.5% 3 h after propranolol administration (p less than 0.05). Labetalol had no significant influence on portal venous hemodynamics. These results support the hypothesis that a decrease in portal venous flow induced by beta blockers is at least partly mediated with alpha-adrenergic receptors.