The addition of lipids increases the total parenteral nutrition-associated cholestasis in the rat.

Cholestasis is one of the most frequent complications of Total Parenteral Nutrition (TPN). Among the components of TPN, amino acids (AA) and dextrose are considered responsible in terms of quantity. The aim of this study was to determine whether IV lipids have a protective effect on the liver lesions induced by TPN, as well as on the bile flow in rats. Two groups of 6 animals, 6 receiving TPN containing AA and dextrose (Group A-D) and 6 receiving AA, dextrose and lipids (Group A-D-L) were studied. Both groups received the same amount of AA (3.4 g/day) and the same amount of energy (50 kcal/day). The TPN lasted 3 days, after which blood samples were obtained for liver function tests and the bile flow was determined gravimetrically, subsequently the liver was removed for histological analysis. A significant weight loss (p < 0.01) was observed in both groups (Group A-D: -13 +/- 4 g; Group A-D-L: -16 +/- 2g). The bile flow was significantly lowered in A-D-L at 10.14 +/- 1.27 microliters/minute when compared to Group A-D (15.61 +/- 1.31 microliters/minute). The Aspartate Amino Transferase (AST) plasma level was elevated at 188 +/- 20 UI in Group A-D and at 185 +/- 33 UI in Group A-D-L. Gamma-Glutamyl-Transferase (gamma-GT) plasma level was in the normal range in both groups. In conclusion, this study indicates that TPN-associated cholestasis is significantly increased by lipid addition. However, the hepatocellular necrosis seems unchanged.