Tomotaka Ueno1, Naoki Tanaka2, Hirofumi Imoto1, Masamitsu Maekawa3, Atsushi Kohyama1, Kazuhiro Watanabe1, Fuyuhiko Motoi1, Takashi Kamei1, Michiaki Unno1, Takeshi Naitoh1. 1. Department of Surgery, Tohoku University Graduate School of Medicine, 1-1, Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan. 2. Department of Surgery, Tohoku University Graduate School of Medicine, 1-1, Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan. n-tanaka@surg.med.tohoku.ac.jp. 3. Department of Pharmaceutical Sciences, Tohoku University Hospital, 1-1, Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
Abstract
BACKGROUND: Bile acids (BAs) are important in the metabolic effects of bariatric surgery. Most BAs are reabsorbed in the ileum and recycled back to the liver. We have reported that this enterohepatic circulation was shortened by duodenal-jejunal bypass (DJB), and the biliopancreatic (BP)-limb plays an important role in reabsorption of BAs. However, the mechanism of BA reabsorption in BP-limb remains uncertain. We aimed to investigate the mechanisms of BA reabsorption after DJB, especially focusing on carrier-mediated transport of BAs and the impact of the presence or absence of lipids on BA reabsorption. METHODS: Otsuka-Long-Evans-Tokushima fatty rats or Sprague-Dawley rats were assigned to a control group and DJB group. BA levels in the divided small intestine were quantified with liquid chromatography-mass spectrometry. Labeled BA was injected and perfused with BA transporter inhibitors or mixture of lipids in the isolated BP-limb, and bile was sampled and analyzed. RESULTS: Conjugated BA levels in the BP-limb were significantly higher than that of the control group. BA absorption tended to decrease by the apical sodium-dependent BA transporter inhibitor and was significantly decreased by the organic anion-transporting peptide (OATP) inhibitor. BA absorption tended to increase in the absence of lipid solutions compared with that in the presence of lipid solutions. CONCLUSION: We attributed the increased BA reabsorption in the BP-limb to lack of food in the BP-limb, which contains concentrated BAs and no lipids. OATP played an important role in BA reabsorption in the BP-limb. Therefore, BAs would be reabsorbed in different manners after DJB.
BACKGROUND:Bile acids (BAs) are important in the metabolic effects of bariatric surgery. Most BAs are reabsorbed in the ileum and recycled back to the liver. We have reported that this enterohepatic circulation was shortened by duodenal-jejunal bypass (DJB), and the biliopancreatic (BP)-limb plays an important role in reabsorption of BAs. However, the mechanism of BA reabsorption in BP-limb remains uncertain. We aimed to investigate the mechanisms of BA reabsorption after DJB, especially focusing on carrier-mediated transport of BAs and the impact of the presence or absence of lipids on BA reabsorption. METHODS: Otsuka-Long-Evans-Tokushima fatty rats or Sprague-Dawley rats were assigned to a control group and DJB group. BA levels in the divided small intestine were quantified with liquid chromatography-mass spectrometry. Labeled BA was injected and perfused with BA transporter inhibitors or mixture of lipids in the isolated BP-limb, and bile was sampled and analyzed. RESULTS: Conjugated BA levels in the BP-limb were significantly higher than that of the control group. BA absorption tended to decrease by the apical sodium-dependent BA transporter inhibitor and was significantly decreased by the organic anion-transporting peptide (OATP) inhibitor. BA absorption tended to increase in the absence of lipid solutions compared with that in the presence of lipid solutions. CONCLUSION: We attributed the increased BA reabsorption in the BP-limb to lack of food in the BP-limb, which contains concentrated BAs and no lipids. OATP played an important role in BA reabsorption in the BP-limb. Therefore, BAs would be reabsorbed in different manners after DJB.
Entities:
Keywords:
Bile acid transporter; Bile acids; Biliopancreatic limb; Duodenal-jejunal bypass; Organic anion-transporting peptide
Authors: Mohammed K Hankir; Theresa Langseder; Ezgi Eyluel Bankoglu; Yalda Ghoreishi; Ulrich Dischinger; Max Kurlbaum; Matthias Kroiss; Christoph Otto; Carel W le Roux; Tulika Arora; Florian Seyfried; Nicolas Schlegel Journal: iScience Date: 2020-11-05