Background/purpose: Dramatic improvement in small bowel lengthening and in weight gain has been demonstrated in newborn rats treated with human growth hormone (GH) after massive small bowel resection. The aim of this study was to confirm these results in another animal model and to specify the part food intake plays in small bowel lengthening induced by GH.
Methods: Twenty-five piglets underwent laparotomy at day 28 of life. Intestinal length was measured under general anesthesia, and animals had an 80% resection of small bowel, leaving a similar length of jejunum and ileon. There were no perioperative deaths. One animal died 3 days after surgery. Animals were assigned to five groups: (1) S (n = 4): sham, mere laparotomy; (2) GH-S (n = 4): sham and GH treatment (0.1 IU/kg/d subcutaneously); (3) R (n = 7): intestinal resection; (4) GH-R (n = 6); and (5) GH-R AdL (n = 4): intestinal resection and GH treatment. S, GH-R, and GH-R AdL had a free diet; GH-S and GH-R were pair-fed with S and R, respectively. Animals were killed 28 days later.
Results: Weight gain was not different in the two nonresected groups (S, 144 +/- 6% of initial weight; GH-S, 150 +/- 3%) and was significantly higher than in the resected groups (R, 67 +/- 28%; GH-R, 74 +/- 16%; GH-R AdL, 55 +/- 16%; NS). GH did not enhance small bowel lengthening in the nonresected groups; S, 41.9 +/- 23% and GH-S, 36.9 +/- 9%, in sharp contrast with the resected groups; R, 28 +/- 9 cm versus GH-R, 96 +/- 39 cm (P = .0008) and versus GH-R AdL, 89 +/- 41 cm (P = .003). Compared with initial length, the increase was R, 16.2 +/- 5%; GH-R, 56.5 +/- 24%; GH-R AdL, 51 +/- 25%. Villus height and diameter, average number of mitosis per field, intestinal muscular layer, wall thickness, and crypt ratio were higher in resected groups than in unresected ones, with no difference observed between resected groups.
Conclusions: GH improves the postoperative intestinal adaptation process after massive small bowel resection in newborn piglets in terms of small bowel lengthening. In contrast to rats, GH did not improve weight gain. In addition, no difference was observed whether animals were on a free or a controlled diet.