Transgenic mice hemizygously carrying human c-Ha-ras proto-oncogene, TgrasH2 show very sensitive and facilitated carcinogenicity to various carcinogens. In this study, activities of certain enzymes related to drug metabolism and energy metabolism were measured in microsome and cytosol fractions of livers of Tg-rasH2 mice and their wild type littermates with both sexes treated with 3-methylcholanthrene (MC) and phenobarbital (PB). Aminopyrine N-demethylase activities increased significantly in livers of all mice treated with PB. MC and PB treatments induced significant increases in activities of UDP-glucuronosyltransferase and S-adenosyl homocysteinase compared to those in the non-treated groups in microsome fractions from all mice. In cytosol fractions of livers of all mice, glutathione S-transferase activity was significantly induced in the PB treated groups. There were no significant differences in activities of lactate dehydrogenase, glucose 6-phosphate dehydrogenase, pyruvate kinase and glucose 6-phosphatase related to energy metabolism in livers and kidneys among all mice. TgrasH2 mice showed stable activities of enzymes related to drug detoxication and energy metabolism similar to those of non-transgenic mice. These results suggest that the human c-Ha-ras transgene may not affect drug metabolism-related enzymes, and the facilitated carcinogenic response in the Tg-rasH2 mouse is not due to these enzymatic disorders.

SummaryPlasma glucose and lipid concentrations and hepatic enzyme activiti es were measured in male ddY mice supplemented with the herb, Ec h e va ria gla uc a , to examine the effect of herbal treatm ent. In mice supplemented with the herb, plasma triglyceride (T G ) and free fatt y acid (FFA) concentrations decreased and hepatic glyc olytic enzyme and glutathione peroxidase (GSHpx) act ivities increased significantly compared with those in the nontreated control mice. T hese increases in hepatic enzyme activities were not fully dosedependent, however the higher dose and longer duration with herb supplement induced increases in the enzyme acti vities. It was found that dietary herb supplement caused an acceleration of hepatic function, judged by increased act ivities of glycolytic enzyme and GSHpx in ddY mice.