Rehabilitation of microsomal enzymes in malnourished rats: Comparison of parenteral versus oral refeeding

Protein malnutrition decreases the activity of drug-metabolizing liver microsomal enzymes. In the first part of our study, we evaluated those enzymes during malnutrition and refeeding. Then we compared the effects of different nutritional patterns on these parameters. During malnutrition (M), rats were fed a 5% casein diet. During refeeding, they were randomized in 3 groups: oral refeeding (20% casein diet: A), continuous total parenteral nutrition (TPN: B) and oral energy refeeding (glucose + lipids) + continuous amino-acid infusion (C). Rats were sacrificed before and at various times during malnutrition and refeeding (2 to 28 days). There was no difference in caloric intake between the 3 groups. Nitrogen balance was not different in A and B. It was lower in C, though nitrogen intake was not different. Body and liver weights were not different between the 3 groups. Microsomal proteins and cytochrome P-450 were improved in A and B but not in C compared to M. Our results suggest that TPN (but not continuous amino-acids infusion + oral energy intake) is as effective as oral nutrition on rehabilitation of microsomal enzymes in malnourished rats.