Plasma Clearance and Tissue Distribution of Dextran Following Infusion of 7.5% NaCl/6% Dextran-70 Euvolemic and Hemorrhaged Rabbits

Dextran metabolism was evaluated in euvolemic and hemorrhaged rabbits following administration of a 7.5 NaCl6 Dextran-70 HSD solution. Control rabbits and those bled 8 mlkg body weight were infused i.v. with 4 mlkg of HSD or HSD containing c-Dextran-70. Blood samples were withdrawn prior to and 0.17, 0.5, 1, 2, 4, 6, 24, 48, 72, and 96 hours after HSD infusion. Although peak serum dextran concentrations were about 29 higher in hemorrhaged rabbits than in controls, in both groups of rabbits dextran was cleared from serum with a half-life of about 7.4 h. In addition, dextran was distributed throughout the blood volume and did not bind to serum proteins. At the end of the 96 h experimental period, concentrations of radiolabeled dextran were 20-fold higher in liver from both groups of rabbits, in comparison to spleen, lung and kidney. The c-dextran in liver was associated with the cytosolic fraction and was not associated with any membrane structures. Molecular weight distribution of the serum dextran revealed no significant metabolism over the 6 h post-infusion period assayed. After 96 h, radiolabeled dextran in liver showed some degree of metabolism and dextranase activity in liver was markedly higher than in the other tissues assayed.