Reduced ileal taurocholate absorption with total parenteral nutrition

Total parenteral nutrition is associated with decreased primary bile acid output. This may result from reduced synthesis or decreased absorption of primary bile acids in the enterohepatic circulation. Ileal atrophy occurs with total parenteral nutrition, and we postulated that absorption of primary bile acids is reduced. Ileal absorption of taurocholate was investigated in miniswine on total parenteral nutrition and this was compared to orally fed animals. Following cholecystectomy and bile duct cannulation, 20 cm, of ileum was perfused with taurocholate. Since miniswine have no significant endogenous taurocholate secretion, the measured taurocholate output reflected ileal absorption. To examine uptake and secretion of taurocholate by the liver, pigs on total parenteral nutrition and controls were infused with intravenous taurocholate (0.5 to 2.5 mumole/kg/min), and bile acid output was determined. Baseline bile acid output was decreased in animals on total parenteral nutrition, yet the response to intravenous taurocholate was similar to controls. When taurocholate was perfused in the ileum, taurocholate output was markedly different. Taurocholate output (pmole/cm ileum/min) at the taurocholate perfusate concentrations of 3 and 20 mM was, respectively, 65 +/- 14 and 183 +/- 63 for controls and 18 +/- 3 and 63 +/- 17 for miniswine on total parenteral nutrition. The latter group's output was significantly lower, at P < 0.05. Both groups of pigs had equal increases in bile acid output with intravenous infusion of taurocholate, suggesting normal hepatic uptake and secretion. Ileal perfusion with taurocholate, however, resulted in decreased taurocholate output with total parenteral nutrition due to decreased ileal absorption of bile acids.(ABSTRACT TRUNCATED AT 250 WORDS)