The mutagenicity of human bile was examined in the Ames Salmonella/mic
rosome assay. Bile samples were obtained from the gallbladders resecte
d from patients with cholelithiasis, choledocholithiasis, gallbladder
cancer, extrahepatic bile duct cancer and other diseases. For extracti
on of mutagenic components, the bile samples were treated with blue ra
yon and the adsorbed materials were assayed with Salmonella typhimuriu
m TA98 in the presence of S9 mix. Twenty-four bile samples were tested
and positive mutagenic activity was found in 14 samples. A 200-mul bi
le equivalent material gave 6.3 times as many revertant colonies as th
e solvent control. With several samples that had undergone two cycles
of blue rayon extraction, clear dose-response relationships in mutagen
icity were demonstrated.