抄録
Degradation and excretion of Sizofiran (SPG), an anti-tumor polysaccharide, were studied in rats after a single or multiple administration. After a single intravenous injection of [14C] SPG (3 mg/kg), SPG distributed in the liver was degradated at very slow rate to SPG-like substances (SPGLS) having lower molecular weight than that of SPG, while SPG in the spleen and mesenteric lymph node was metabolized at much slower rate than that in the liver. In the experiment with multiple subcutaneous administration, SPG was also found to be present mainly as SPGLS in the liver, but almost as an unchanged SPG in the spleen. SPG was excreted in the urine mainly as metabolites with a molecular weight of less than 10000. These results indicate that degradation of SPG to lower molecular weight-SPGLS is a prerequisite for efficient urinary excretion and the degradation occurs mainly in the liver.
