Capacitance Responses and Fluid Exchange in the Cat Liver during Stimulation of the Hepatic Nerves

Techniques are described to study the hepatic vascular bed in the anesthetized cat without interference with the hepatic artery or portal vein. Liver volume was recorded with a plethysmograph while simultaneous recordings were made of arterial and portal pressures and total hepatic blood flow. Hepatic venous pressure could be raised to any desired level, and capillary filtration coefficients could therefore be determined. The hepatic blood volume was 27 ± 3.3 ml/100 g liver (14% of the total blood volume of the cat). Stimulation of the hepatic nerves decreased liver volume. Maximal responses were reached at frequencies of about 6/sec, and 50% of the blood in the liver was expelled. The hepatic vascular bed is thus an important blood reservoir. The capillary filtration coefficient was 0.30 ± 0.03 ml/min/mm Hg/100 g, and this value was not significantly changed during stimulation of the hepatic nerves.