The LEC Rat pp 305-312 | Cite as

The Multistep Nature of Spontaneous Liver Cancer Development in the LEC Rat: Analysis of Incidence and Phenotype of Preneoplastic and Neoplastic Liver Lesions

  • Katsuhiko Enomoto
  • Masakuni Sawaki
  • Hidetoshi Takahashi
  • Yasuo Nakajima
  • Kimimaro Dempo
  • Michio Mori


The LEC rat has been established and characterized as a new mutant strain which spontaneously develops hepatitis and liver cancer at an extremely high incidence. The LEC rat manifests severe hereditary hepatitis with systemic jaundice and hemorrhagic tendency at around 4 months after birth. About 30%–40% of the rats die during the period of hepatitis because of submassive or massive necrosis of hepatocytes. The remaining rats recover from severe hepatitis and survive more than 1 year. Histopathological examination of the livers of the long-survived LEC rats shows development of preneoplastic and neoplastic lesions at a high incidence with continued hepatocyte death and regeneration (prolonged hepatitis) [1, 2].


Liver Lesion Severe Hepatitis Hyperplastic Nodule Liver Carcinogenesis Spontaneous Liver 
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  1. 1.
    Masuda R, Yoshida MC, Sasaki M, Dempo K, Mori M (1988) High susceptibility to hepatocellular carcinoma development in LEC rats with hereditary hepatitis. Jpn J Cancer Res (Gann) 79:828–835.CrossRefGoogle Scholar
  2. 2.
    Enomoto K, Takahashi H, Sawaki M, Sawada N, Ikeda T, Hattori A, Mori M (1989) High incidence of spontaneous hepatocellular carcinoma in a new mutant rat of hereditary hepatitis. Proc Am Assoc Cancer Res 30:194.Google Scholar
  3. 3.
    Ogawa K, Solt D, Farber E (1980) Phenotypic diversity as an early property of putative preneoplastic hepatocyte populations in liver carcinogenesis. Cancer Res 40:725–733.PubMedGoogle Scholar
  4. 4.
    Enomoto K, Ying TS, Griffin M, Farber E (1981) Immunohistochemical study of epoxide hydrolase during experimental liver carcinogenesis. Cancer Res 41:3281–3287.PubMedGoogle Scholar
  5. 5.
    Rous P, Kidd JG (1941) Conditional neoplasms and subthreshold neoplastic states: A study of the tar tumors of rabbits. J Exp Med 73:369–390.CrossRefGoogle Scholar
  6. 6.
    Unger H, Adler JH (1978) The histogenesis of hepatoma occurring spontaneously in a strain of sand rats (Psammoncys obesus) Am J Pathol 90:399–410.Google Scholar
  7. 7.
    Goodman DG, Ward JM, Squire RA, Chu KC, Linhart MS (1979) Neoplastic and nonneoplastic lesions in aging F344 rats. Toxicol Appl Pharmacol 48:237–248.PubMedCrossRefGoogle Scholar
  8. 8.
    Ward JM (1981) Morphology of foci of altered hepatocytes and naturally occurring hepatocellular tumors in F344 rats. Virchows Arch [A] 390:339–345.CrossRefGoogle Scholar
  9. 9.
    Harada T, Maronpot RR, Morris RW, Stitzel KA, Boorman GA (1989) Morphological and stereological characterization of hepatic foci of cellular alteration in control Fischer 344 rats. Toxicol Pathol 17:579–593.PubMedGoogle Scholar
  10. 10.
    Oyamada M, Dempo K, Fujimoto Y, Takahashi H, Satoh MI, Mori M, Masuda R, Yoshida MC, Satoh K, Sato K (1988) Spontaneous occurrence of placental glutathione S-transferase-positive foci in the livers of LEC rats. Jpn J Cancer Res (Gann) 79:5–8.CrossRefGoogle Scholar
  11. 11.
    Takahashi H, Enomoto K, Nakajima Y, Mori M (1990) High sensitivity of the LEC rat liver to the carcinogenic effect of diethylnitrosamine. Cancer Lett 51:247–250.PubMedCrossRefGoogle Scholar
  12. 12.
    Schulte-Herman R, Timmerman-Trosiener I, Scuppler J (1983) Promotion of spontaneous preneoplastic cells in rat liver as a possible explanation of tumor production by nonmutagenic compounds. Cancer Res 43:830–844.Google Scholar

Copyright information

© Springer-Verlag Tokyo 1991

Authors and Affiliations

  • Katsuhiko Enomoto
  • Masakuni Sawaki
  • Hidetoshi Takahashi
  • Yasuo Nakajima
  • Kimimaro Dempo
  • Michio Mori
    • 1
  1. 1.Department of PathologySapporo Medical CollegeSapporo, 060Japan

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