COMPARISON OF MUTAGENIC ACTIVITY OF BILE BETWEEN CHILEAN AND JAPANESEFEMALE-PATIENTS HAVING CHOLELITHIASIS

The mutagenic activity of bile was compared between Chilean and Japane se female patients having cholelithiasis by the Ames assay using Salmo nella typhimurium tester strain TA98 in the presence of S9 mix with bl ue rayon adsorption technique. A reason for conducting the present inv estigation is that Chile and Japan have the highest mortality rates fo r the gallbladder cancer (GBC) in the world. Of 24 bile samples collec ted in Chile, 20 (83.3%) samples showed mutagenicity. In the case of J apanese bile, 21 (80.8%) of 26 and 5 (19.2%) of 26 cases were mutageni c in samples from high- and low-risk areas for GBC, respectively. Ther efore, both the Chilean and the Japanese samples collected in high-ris k areas showed higher mutagenic rates than the Japanese ones in a low- risk area, with a statistical significance (p < 0.001, chi-square test ). The average number of revertant colonies were 128 +/- 92 (mean +/- SD), 62 +/- 14 and 66 +/- 13, respectively, when the blue rayon extrac ts of 200 mu l bile were applied to the Ames test. Thus, Chilean bile had a tendency to show a higher mutagenic activity than Japanese.