Pentoxifylline does not influence maximum ultrafiltration rates and peritoneal transport in rats

Previous publications have suggested that peritoneal capillary blood flow and filtration pressure equilibrium may limit ultrafiltration rates with very hypertonic exchanges. Rats were treated with pentoxifylline, which decreases blood viscosity by increasing red blood cell deformability. Decreases in blood viscosity should reduce microcirculatory resistance and increase effective capillary flow. Transport studies were performed after 2, 4, and 8 weeks of therapy with peritoneal dialysis solutions containing 15 grams % dextrose and using 30-min cycles. Even though rats ingested near the maximum recommended dose of pentoxifylline (20 mg/kg) significant changes in blood viscosity and shear stress were not detected compared to controls. Also, there were no significant differences in clearances of urea and phosphorus, glucose absorption, protein losses, and net ultrafiltration compared to controls.