Document 51ryrX7ke5Ldv15VKD422d20

7 r* fc tafcltftATto *U*UA W .3U**-ym. i COMMUNICATION [GANN, 63, 805; December, 1972] GDC 616-OOG-O21.6[616.36] :547.621-38 HEPATOCARCINOGENICITV OF POLYCHLORINATED , BIPHENYLS IN MICE ' The acute and chronic toxicity of poly chlorinated biphenyls (PCB) in mice, rats, and dogs has been reported by many workers.') This communication reports studies on hepatocarcinogcnic effect of polychlorinated biphenyls in dd mice. Male dd mice with an average weight of 19.0g were used. A total of 114 mice were divided into the following 10 groups and the animals were fed on a basal diet (Oriental KMF) supplemented with various kinds of polychlorinated biphenyls, Kanccrol-500, KanecroMOO, and Kanccrol-300 which are classified by the number of chlorines, purchased from Kancgafuchi Chem. Co., Osaka. Group 1, 500 ppm Kanccrol-500; Group 2, 250 ppin Kanecrol-500; Group 3, 100 ppm Kanecrol500; Group 4, 500 ppm KanecroMOO; Group 5, 250 ppni KanecroMOO; Group G, 100 ppm KanecroMOO; Group 7, 500 ppm Kanccrol300; Group 8, 250 ppm Kanccrol-300; Group 9, 100 ppm Kanccrol-300; Group 10, basal diet alone. F.ach group contained 6 to 12 mice. The animals were given water and the experi mental diet freely. After 32 weeks, mice were sacrificed with ether and examined histologi cally. Grossly, 7 of the 12 mice (58.3%) in Group 1 had many tumors in the liver. The liver in- creased in weight, and had a rough surface with multiple tumors up to 0.2 to 1.0 cm in diameter. In other groups, except in Groups 1 to 3, no remarkable changes were observed in the liver ofmice. Microscopically, hepatomas were observed in the liver of mice in Group 1. Some area of nodules showed adenomatous pattern. Many necrotic foci were seen in Group I animals. Nuclear irregularities and mitotic figures were frequently seen in nontumorous areas of the liver in Group 1. How ever, microscopical change? in the liver were not observed in Groups 4 to 9. From the present results, the hepatomas in duced in mice by the Kanec.rol-500 of poly chlorinated biphenyls appeared similar to those induced by a-isomcr of benzene hexacholoridc*) but KanecroMOO and Kanccrol300 of polychlorinated biphenyls had no carcinogenic activity in the iver of mice. This work will be reported in Idctail later. REVERENCES 1) McLaughlin, J., Jr., it el., Toxicol. Afi/d. Thamecol., 5, 700 (1963); I.ichenskin, E. P., ft el., J. Econ. Enlomol., 62, 761 (1969); Hansen, D. J., et el.. Bull. Environ. Contam. Toxicol., 6, 113 (1971). 2) Nagasaki, H., <1 at., GANN, 62, 431 (1971); Nagasaki, H., et at., GANK, 63, 393 (1972). Depnitmcnt of Hygiene. Nora Hygienic Institute Cancer Center Institute Nara Medical Uniiosity, Kashihora, Kara 634 Hiroshi Nagasaki Shosukc Tomii Tomoichi Mega Masao Marugami Nobuyuki I to (P<*7 37.) (HiH-ttMi) (SfcilftLfc--) W3rr) 63(C) 1972 DSW 031188 805 STLCOPCB4015150