Imbalance between Jejunum and Ileum in the Response of Brush Border Hydrolases to Oral Feeding after Intravenous Alimentation in Rats

ABSTRACT. The effect of oral refeeding after total parenteral nutrition (TPN) on brush border hydrolases was measured in the proximal jejunum and ileum of adult rats. The animals received intravenously for 4 days a mixture of Intralipid 10% and Vamine-Glucose. At the end of TPN, oral feeding was reinstituted and the rats were fed with an isocaloric standard diet (60 % carbohydrate, 17 % protein, 3 % lipid). Sucrase, iso-maltase, lactase, and aminopeptidase N activities were meas-ured at the end of TPN and at 1, 3, and 5 days after TPN. Sham-operated rats nourished orally with the standard diet were used as controls. In both intestinal segments, lactase activity showed no significant changes at the end of TPN or during oral realimentation. Isomaltase, and especially sucrase activities, exhibited an important drop at the end of TPN. After TPN, a complete restoration of isomaltase and sucrase activi