Geographical variations in the concentration of biliary free fatty acids with anti-mutagenic action

The concentrations and compositions of free fatty acids (FFAs) in human bil e, especially of inhibitory free fatty acids (IFFAs), were analyzed in term s of anti-mutagenic effects in relation to the mutagenic activity of bile. Bile samples were collected from patients with cholelithiasis residing in e ither Niigata or Kochi prefectures of Japan, regions characterized as the h ighest and lowest risk areas for gallbladder cancer (GBC), respectively. Bi liary FFAs and IFFAs were analyzed by high-performance liquid chromatograph y aod mutagenicity was examined in by me Amen lest (TA98 + S9mix) after blu e rayon treatment. There was a tendency for higher biliary FFA and IFFA con centrations in the Kochi subjects, but the proportion of IFFA to the total FFA concentration did not differ between the two areas. There was an invers e correlation between the concentrations of IFFAs and the numbers of revert ant colonies in both Niigata and Kochi subjects. However, at a dose of 591 mu mol/l, (calculated based on the average amount of IFFAs absorbed in blue rayon) IFFAs did not exhibit anti-mutagenic actions in the blue rayon extr acts. Within this range, more positive samples were seen in Niigata than in Kochi, suggesting the presence of more active mutagen(s) in Niigata sample s. (C) 1999 Elsevier Science B.V. All rights reserved.