Front the *Departments of Surgely and SPhamiacy, Saint Joseph Hospital, Denaec l.Veteraits Administration hledical Center, hleinplzis;

ABSTRACT. In addition to its role in absorbing nutrients, the intestinal mucosa provides an important barrier against toxins and bacteria in the bowel lumen. This study evaluated changes in rat jejunal permeability and histology after total parenteral nutrition (TPN) or TPN supplemented with glutamine. Lactulose and mannitol were used to measure jejunal permeability, and fured stained histologic specimens were used to measure mucosal dimensions. After the insertion of central venous catheters, 18 male rats were randomly divided into three groups: CHOW, saline infusion with a standard laboratory rat diet ad libitum; TPN; and GLN, 2% bglutamine-supplemented TPN. The TPN and GLN groups received isocaloric, isovolumic, and isonitrogenous feedings. After 7 days of infusion, a laparotomy was performed, and lactulose and mannitol were instilled into the lumen of