Suppression of liver uptake of liposomes by dextran sulfate 500.

The effect of dextran sulfate (DS, 500,000 Mr) and multilamellar vesicles (MLV) as liver blockade agents has been investigated in mice. Intravenous injection of unlabeled MLV prior to radioactive MLV caused moderate reduction in the liver uptake and increased tibia, lung, and spleen uptake. More drastic differences were observed with intraperitoneal injection of DS. When tested in the range of 0-50 mg of DS per kg of body weight, maximal liver blockade occurred at a dose of 50 mg. By using 50 mg of DS per kg, maximal liver blockade occurred at 12 hr after DS injection. The liver blockade was temporary, ending within 48 hr. The intraperitoneal route of injection for DS was more effective for liver blockade than the intravenous route.