OBJECTIVE.: To validate the experimental model of Larrad-biliopancreatic diversion (LBPD) and to analyze weight gain and mortality in rats fed with non- supplemented diets.
Material and method: Control (6) and experimental (10) male Wistar rats were used. The experimental group was operated on using the human LBPD adapted for rats: Subcardial gastrectomy, a short biliopancreatic channel created at 5 cm from Treitz angle and common channel at 5 cm from ileocecal valve. After surgery recovery (7 days) the rats were fed ab libitum with a standard non-supplemented diet (without proteins, minerals or vitamins). Percentage of weight lost or gained up to the end of the experiment was analyzed.
Results: The control animals gained weight progressively from 13.1 +/- 2.4% at day 7 to 58 +/- 9.2% at day 63, when the animals were sacrificed. After LBPD, mortality was 50% at day 25 +/- 17.5(range, 14-56), no significant differences in the percentage of weight lost being found between surviving (-38.9 +/- 14.2%) and non-surviving rats (-29 +/- 5.6%; p = 0.192). Of the surviving animals, 80% progressively lost weight reaching a maximum loss between day 63 (-42.3 +/- 8%) and 70 (-44.1 +/- 9.7%), and 20% lost weight until day 35 and gained over 7% of body weight until sacrifice (day 147).
Conclusions: An experimental model of LBPD in rats is technically feasible. Both mortality and percentage weight loss are not directly related. The bowel adaptation mechanism could mediate the percentage of weight regain in operated rats.