EXPERIMENTAL SHORT-BOWEL SYNDROME - FREE AMINO-ACID VERSUS INTACT PROTEIN IN NUTRITIONAL SUPPORT

Tile objective of the present study was to evaluate the role of a diet consisting of a free amino acid mixture in the metabolic and nutritio nal response of rats after resection of 80% of the small intestine. Fo rty Wistar rats were divided into four groups of 10 animals respective ly receiving a free amino acid diet (AR and AS groups) and an intact p rotein-casein diet (CR and CS groups). Ten animals in each group were submitted to 80% jejuno-ileal enterectomy (AR and CR), and the remaini ng animals were sham operated. Nitrogen balance (NB), diet digestibili ty, cumulative weight variation (CWV), urinary creatinine excretion, a nd serum albumin levels were determined. A significant difference in N B (p < 0.05) was observed between the AR and CR groups during the imme diate postoperative period (0.10 + 0.01 gN/period vs. -0.11 + 0.04 gN/ period). Tile digestibility of the free amino acid diets also differe d significantly (p < 0.05) when compared to the casein diet during the same period of time (79.2 + 1.1% vs. 46.6 + 2.2%). At the end of the experiment, CWV was -5.1% for Group AR and -7.2% for Group CR (p > 0.0 5) and serum albumin also showed no significant difference between gro ups. During the fourth week after surgery, 24-hour urinary creatinine excretion was significantly greater for AR animals (5.95 + 2.00 mg/24 hours) than for CR animals (4.10 + 1.04 mg/24 hours). We conclude that the free amino acid diet showed a better nutritional performance duri ng the immediate post-enterectomy period, suggesting the possibility o f an early use of these diets after extensive intestinal resection