Tissue Distribution of Intraperitoneally Administered (1→3)-β-D-Glucan (SSG), a Highly Branched Antitumor Glucan, in Mice

Abstract

Distribution of metabolically ³H-labeled (1→3)-β-D-glucan (³H-SSG) obtained from the culture filtrate of Sclerotinia sclerotiorum IFO 9395, in various tissues after intraperitoneal administration into ICR mice (250 μg/mouse) was examined. ³H-SSG was mainly detected in liver, spleen, and blood, and a negligible amount was excreted into the feces and excrement within 2 d. The significant amount of ³H-SSG remained in liver and spleen after 1 month. On the other hand, SSG was not incorporated effectively in vivo and in vitro by peritoneal exudate macrophages (0.5 μg/1×10⁶ Mφ). Similarly in vivo, the majority of ³H-SSG distributed in spleen and liver were recovered from the non-cellular fraction and not from splenic macrophage and Kupffer cell fractions. These results suggested that (1→3)-β-D-glucans would not be easily incorporated by the host cells to degrade and exclude from the body even after the onset of the biological response modifier activity.