THE EFFECTS OF SELECTIVE AND NONSELECTIVE 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 < 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.