Pentoxifylline, a drug with rheological effects, decreases portal pressure in an experimental model of cirrhosis.

OBJECTIVE

To evaluate the influences of blood viscosity changes, mediated by a haemorheological agent, on splanchnic and systemic haemodynamic parameters in rats with cirrhosis due to chronic bile duct ligation.

METHODS

Blood viscosity was measured using a cone-plate viscometer and whole blood filterability was determined by a filtration method. Cardiac index and portal venous inflow were measured using radioactive microspheres. Measurements were performed 30 min after double-blind administration of placebo or pentoxifylline (25 mg/kg, intravenously).

RESULTS

As compared with placebo, pentoxifylline-treated cirrhotic rats had a lower portal pressure (13.8 +/- 1.4 vs. 12.1 +/- 1.6 mmHg, P < 0.05) and blood viscosity at shear rates of 115/s (6.6 +/- 0.8 vs. 5.8 +/- 0.3 mPas, P < 0.05), associated with an improvement of whole blood filterability (45.0 +/- 12.9 vs. 20.0 = 3.9 s/ml, P < 0.01). Similar values of mean arterial pressure, cardiac index and portal venous inflow were observed in both groups. A significant correlation was found between portal pressure and blood viscosity at a shear rate of 115/s (r = 0.71, P < 0.01).

CONCLUSION

These results suggest that portal pressure can be modified by pentoxifylline in an experimental model of cirrhosis. These haemodynamic changes are associated with a lower blood viscosity and whole blood filterability. Pentoxifylline may be a new approach in the treatment of portal hypertension.