Transperitoneal fluid dynamics in rabbit liver.

The peritoneal cavity of 18 anesthetized spontaneously breathing supine rabbits was opened through a midline section. One or two hollow capsules (surface area 0.8 cm2) were glued to the exposed liver surface, filled with whole or 25% diluted plasma, and connected to a transducer and a graduated pipette. Various hydraulic pressures (Pcap) were set in the capsule; at each Pcap the liquid flow per unit surface area (V/S) between the Disse's interstitial space and the capsule was measured from the rate of liquid displacement in the pipette. The slope of the V/S vs. Pcap linear regression was utilized to estimate the hydraulic conductivity of the Glissonian-peritoneal membrane and averaged 5.1 x 10(-3) +/- 4.7 x 10(-3) (SD) ml.h-1.cmH2O-1.cm-2 (n = 25). Hydraulic pressure in the Disse's space (Pd) was measured by closing the capsule against the transducer disconnected from the pipette. At portal and hepatic venous pressures of 7.6 +/- 2.9 and 2.6 +/- 1 cmH2O, respectively, Pd was 2.05 +/- 2 cmH2O. Physiologically, Starling pressure gradients cause fluid transfer from the sinusoids to the Disse's space; transperitoneal fluid filtration only occurs through the liver surface that faces the diaphragm, which corresponds to one-fifth of the total hepatic surface.