Effects of Thyroid Hormone on the Adaptation in Short Bowel Syndrome

Background. Thyroid hormone acts on structural and functional maturation of the mammalian small intestine, mitochondrial pathways, and several protein-gene interactions. Therefore, it is one of the most important regulators of intestinal epithelial differentiation. The aim of the study was to evaluate the effects of thyroid hormone on the adaptation in an experimental model of short bowel syndrome. Methods. Rats were divided into three groups: sham (bowel transection and anastomosis), short bowel syndrome-saline (75% bowel resection and anastomosis), and short bowel syndrome-thyroid hormone (75% bowel resection and anastomosis, and was administered triiodothyronine). The evaluation of adaptation parameters, histopathological and biochemical analysis were performed in all groups. Results. Triiodothyronine treatment resulted in a significant increase in adaptation parameters, villus height-crypt depth, and enterocyte proliferation, whereas significant decrease was seen in apoptotic index in jejunum. Enterocyte proliferation and most of the adaptation parameters changed significantly in ileum following the treatment with triiodothyronine as in jejunum. The changes in ileal villus height-crypt depth and apoptotic index were not statistically significant. Serum levels of free triiodothyronine were lower in the short bowel syndrome-saline group. Conclusions. Our results suggest that thyroid hormone treatment in the hypothyroid phase of SBS enhances intestinal adaptive response. (C) 2009 Elsevier Inc. All rights reserved.