Endocrine Abstracts

Products of carbohydrates, proteins and lipids hydrolysis are absorbed by specific carriers located at the enterocytes apical membrane, but little is known about the mechanisms related to their regulation by own nutrients, especially considering the high consumption of fats. Carbohydrates are transported by SGLT1, GLUT5 and GLUT2 and peptides are transported by PEPT1. Cholesterol is transported by NPC1L1 and long chain fatty acids occur through FAT-CD36 and FATP4. Thyroid hormones have important effects on organic nutrients metabolism, but little is known about their role on the intestine, which led us to evaluate thyroid hormone effects on intestine organic nutrients carriers of mice fed high fat diet (HFD) or standard diet. C57BL/6 mice were fed standard diet (control) or high fat diet (HFD) for 12 weeks. Afterwards, both mice were treated with saline, PTU (antithyroid drug) or T3 for 30 days. They were killed and the jejunum was removed for histological analysis or inverted for intestinal epithelium separation from the mucosa for protein analysis by Western blotting technique. FAT-CD36, NPC1L1 and GLUT2 protein contents reduced in mice fed HFD compared to control mice. SGLT1, PEPT1 and FATP4 remained unchanged among experimental groups. On the other hand, NHE3 protein content, which is important for sodium and peptides absorption, increased significantly in the small intestine of mice fed HFD. PTU or T3 treatment did not affect these parameters. High fat compared to standard diet did not show any alteration of the villus length, but mice fed standard diet and treated with PTU or T3 showed an increased villus length compared to treated-vehicle mice, however this finding have no association with the changes of nutrient carriers described above. Thus, we can infer that HFD affects the expression of some organic nutrient carriers in the small intestine, independently of thyroid hormones treatment.