Splanchnic volume, not flow rate, determines peritoneal permeability.

To distinguish the effects of splanchnic blood flow rate from those of splanchnic volume on peritoneal transfer rates, measurements were made in rabbits before and after intraperitoneal exposure to sodium chromate. The sodium chromate induced reversible hepatic sinusoidal block with consequent portal venous congestion and stasis, which was demonstrable on histologic sections. Concurrently the ultrafiltration rate, and ultrafiltration coefficient each doubled after chromium even though the dialysate reabsorptive rate increased and the absorptive diffusion of glucose was at least as high as in control dialyses. Chromium induced significant increases in mass transfer coefficients of urea, potassium and phosphate and in protein clearance. These data suggest that splanchnic volume is an important determinant of peritoneal transfer functions and that the hepatic capillaries may contribute appreciably to transfer ordinarily ascribed to peritoneal capillaries alone.