|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1995 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1994 : ¥1,400,000 (Direct Cost : ¥1,400,000)
The mutagenicity of human bile was investigated in the Ames test after blue rayon treatment. In the present study. Two main research projects have been undertaken for two years. One is to analyze the mutagenicity of bile collected from Niigata and Kochi, where the mortalities from the gallbladder cancer are the highest and the lowest in Japan, respectively. The other is compara the mutagenic activities of Japanese bile with those from Temuco, Chile, where the mortality from the gallbladder cancer has been the highest in the world.
In the first investigation, 52 and 59 bile samples were collected from Niigata and Kochi. Mutagenicity of blue rayon extracts of bile juice was detected by Ames assay with Salmonella typhimurium TA98 with S9mix.
Thirty-two (61.5%) of 52 samples obtained from the high risk population were mutagenic. In our previous study, the mutagenicity was observed in 14 (58.3%) of 24 samples. After combining this data with the results of the present study, 46 (60.5%) of 76 samples revealed the mutagenicity. On the other hand, the mutagenicity was detected in only 7 (11.9%) of 59 samples collected from the low risk population. Therefore, we found a significantgeographical difference in the bile mutagenicity.
In the second investigation, bile samples were collected only from the female patients with cholelithiasis. Of 24 bile samples in Temuco, Chile, 20 (83.3%) showed the mutagenicity. In the case of Japanese bile, 21 (80.8%) of 26 and 5 (19.2%) of 26 were mutagenic in Niigata and Kochi, respectively. Although the mutagenic activity of Niigata samples does not differ from that of Temuco, Chile, the number of revertant colonies, which stands for the mutagenic power, is lower in Niigata than Trmuco ; 62(]SY.+-.])14 vs 128 (]SY.+-.])92 (mean(]SY.+-.])S.D.). Regardless of the differences in the average numbers of revertant colonies, mutagenic activity increased with age all in the three groups.