engleski

Distribution of sodium-glucose cotransporter 1 (SGLT1) along the porcine small intestine

Carbohydrates make up the largest quantitative and energetic part of the porcine omnivorous nutrition. Transepithelial transport of glucose, the most abundant monosaccharide after carbohydrate digestion, in the small intestine is performed by using a specific membrane transporter located on the brush-border membrane of the enterocyte, the sodium-glucose cotransporter 1 (SGLT1). The aim of this study is to investigate the distribution of SGLT1 expression along the porcine small intestine. The study was conducted on 20 pigs Swedish Landrace breed. At the age of 10 months, the pigs were slaughtered for commercial use and tissue samples of duodenum, jejunum and ileum were taken and analyzed by immunostaining of tissue cryosections and Western blotting with a specific primary SGLT1 antibody. The protein bands obtained by Western blotting were densitometrically measured and analyzed. The immunostaining method confirms the previous described cellular location of SGLT1 on the brush- border membranes of the enterocytes, while the apical membranes of the goblet cells, the cells inside the intestinal crypts and lamina propria of the intestinal villi remained unstained. The Western blotting method gives a ~75 kDa protein band, which corresponds to the SGLT1 protein. Immunostaining of duodenum, jejunum and ileum cryosections shows a significant difference in the fluorescence intensity of the enterocyte membranes, increasing from the duodenum, where it is at lowest, to the ileum, where it is at highest. The results of the immunostaining method are confirmed by Western blotting. The ~75 kDa protein bands are significantly less pronounced in the duodenum than in the jejunum (~2x) and the ileum (~4x). The observed pattern in distribution of SGLT1 expression along the small intestine indicates that jejunum and ileum are the main site of glucose absorption in the small intestine of the pig.

glucose absorption ; small intestine ; SGLT1 ; pig

nije evidentirano