Distribution of grifolan NMF-5N (I/B), a chemically modified antitumor beta-glucan in mice

The distribution of a 3H-labeled chemically modified antitumor beta-glucan, grifolan NMF-5N (I/B), in various tissues after an injection into mice was examined in order to obtain information on distribution of the parent antitumor beta-glucan, grifolan NMF-5N. Grifolan NMF-5N was treated with sodium metaperiodate and sodium borotritide to obtain tritium-labeled grifolan NMF-5N [3H-grifolan (I/B)]. When 3H-grifolan (I/B) was administered into normal mice by intraperitoneal (i.p.) or intravenous (i.v.) injection, radioactivity was detected in various mouse tissues. Next, 3H-grifolan (I/B) was injected into tumor-bearing mice 7 d after the tumor inoculation, which is the most effective administration timing for the antitumor effect of grifolan NMF-5N. The results indicated a strong radioactivity in spleens and tumor masses. These results suggested a close relationship between the antitumor activity and the distribution of grifolan NMF-5N in mice.