Biliary flow rate and concentration of Fe, Cu and Mn as affected by enteral or parenteral Ni supply

Five and three bile duct cannulated 45 kg pigs were used in two experiments to evaluate the effects of nickel on the biliary excretion of iron, copper and manganese. In control periods the animals consumed 1.5 mg Ni per day (1 mg/kg diet), and in the respective treatment periods they further received 90 mg Ni per day (60 mg/kg diet) orally or 1.5 mg Ni per day intravenously. Oral supplementation of nickel had no significant effect on biliary iron, whereas the secretion rate of copper was increased by about 50%, and manganese secretion was reduced to about 50% of the control value. Parenteral administration of nickel had no significant effect on biliary iron, copper and manganese secretion. Iron and copper secretion rates were highest after feeding, whereas the pattern of manganese secretion was characterized by a predominant noctural peak irrespective of the treatments in both experiments.