DOSE-DEPENDENT ENHANCING EFFECT OF PHENOBARBITAL ON HEPATOCARCINOGENESIS INITIATED BY DIETHYLNITROSAMINE IN THE RAT

  • 1 January 1981
    • journal article
    • research article
    • Vol. 72  (1) , 170-173
Abstract
Sequential feeding of various dose levels of phenobarbital (PB) after diethylnitrosamine (DENA) administration revealed that the enhancing effect of PB on hepatocarcinogenesis was dose-dependent. The highest dose level of PB, 0.2% in the diet, greatly enhanced the formation of tumors > 5 mm in diameter. Tumors obtained in the 0.2% PB feeding group were more numerous and larger in size than those in the 0.01, 0.05 and 0.1% PB feeding groups. Although it took longer, the enhancing effect of 0.01% PB feeding was evident when DENA had been administered for 3 wk, while the same dose level of PB clearly enhanced hepatocarcinogenesis when the carcinogen had been given for 5 wk.