EFFECTS OF EXOGENOUS NEUROTENSIN ON INTESTINAL POSTRESECTIONAL GROWTHIN THE SUCKLING RAT

Background: In the suckling rat, massive bowel resection provokes inte stinal malabsorption that leads to diminished growth. The object of th is report was to test whether neurotensin, intestinal trophic peptide, enhances postresection intestinal adaptation, improving absorption an d reducing the adverse effects of resection on growth. Methods: Fifty- seven 15-day-old suckling Wistar rats were divided into four groups: 4 1 rats were subjected to resection of 90% of their small bowel, while the rest (n = 16) underwent laparotomy. Half of the animals, resected and laparotomized, were treated with neurotensin for 30 days. The body weight was monitored, and samples of bone and intestinal mucosa were obtained at the end of the study period for analysis. Blood was tested to determine iron, ferritin, folic acid, and vitamin B-12 levels. Res ults: The resected animals lost body weight regardless of neurotensin administration. In the resected animals, femur weight increased signif icantly when they received neurotensin. Bowel resection provokes signi ficant increases in the intestinal mucosa (crypts and villi), but afte r neurotensin administration, significant increases were detected only in the jejunum of the resected animals but not in the ileum of laparo tomized rats. In the resected animals, signficant decreases in iron, f erritin, folic acid, and vitamin B-12 levels were observed. The postre section administration of neurotensin only produced a significant rise in the ferritin concentration. Conclusions: In the suckling rat, neur otensin enhances the intestinal proliferative phenomenon but does not improve the course of medium-term postresection growth.