Effects of Hepatic Venous Pressure on Transsinusoidal Fluid Transfer in the Liver of the Anesthetized Cat

Abstract

Arterial pressure, portal pressure, hepatic venous pressure, and hepatic volume were measured simultaneously in anesthetized cats. When hepatic venous pressure was raised, hepatic volume increased at first rapidly then slowly. After 20 minutes, the volume increased at a steady rate which continued for at least 4 hours. During this period, the hepatic blood volume ( 51 Cr-tagged red blood cells) was constant, and fluid with a high protein content accumulated in the plethysmograph. When the hepatic lymphatics were tied, the rate of filtration (0.060 ± 0.003 ml · min -1 · mm Hg -1 · 100 g -1 ) was directly proportional to the hepatic venous pressure. When hepatic venous pressure was restored to zero, the filtered fluid was not reabsorbed by the liver. The data are discussed in relation to Starling's hypothesis and the formation of ascites. It is concluded that transsinusoidal fluid filtration in the liver is dependent on the sinusoidal hydrostatic pressure and that no protective mechanisms are available to prevent filtration when hepatic venous pressure is raised for long periods.