Altered glycine and taurine conjugation of bile acids following aluminum administration to rats

Aluminum contaminates components of intravenous nutrient solutions and accumulates in the liver with parenteral feeding. Abnormalities in hepatic function associated with aluminum accumulation include increased serum bile acid concentration and glucuronyl transferase activity and reduced mixed function oxidase levels and bile flow. Whether there are other biochemical responses of the liver to aluminum is unclear. We report the effects of aluminum administration on bile acid conjugation in rats given aluminum intravenously as follows: Group I, 1 mg/kg/day for 14 days; group II, 5 mg/kg/dayfor 14 days; and group III, 5 mg/kg/day for 7 days. Tau-rine-conjugated bile acids were reduced and glycine/taurine elevated in all groups compared with pair-fed controls. Glycine/taurine was greater in group II versus III and varied directly with serum bile acid concentration. These findings suggest that aluminum administration is associated with decreased taurine conjugation of bile acids, a phenomenon that may be associated with cholestasis.