Basal leptin regulates amino acid uptake in polarized Caco-2 cells
| Autor: | Carmen Fanjul, María Pilar Lostao, Jaione Barrenetxe |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Leptin
medicine.medical_specialty Physiology Glycine Biology Basolateral compartment Tritium Biochemistry Intestinal absorption Internal medicine medicine Humans Receptor Epithelial polarity chemistry.chemical_classification Leptin receptor Amino acids transport digestive oral and skin physiology Cell Polarity Biological Transport Caco-2 General Medicine Apical membrane Amino acid Kinetics Endocrinology chemistry beta-Alanine Receptors Leptin Scintillation Counting Caco-2 Cells hormones hormone substitutes and hormone antagonists |
| Zdroj: | Dadun. Depósito Académico Digital de la Universidad de Navarra instname |
| Popis: | Leptin is secreted by gastric mucosa and is able to reach the intestinal lumen where its receptors are located in the apical membrane of the enterocytes. We have previously demonstrated that apical leptin inhibits sugar and amino acids uptake in vitro and glucose absorption in vivo. Since leptin receptors are also expressed in the basolateral membrane of the enterocytes, the aim of the present work was to investigate whether leptin acting from the basolateral side could also regulate amino acid uptake. Tritiated Gln and β-Ala were used to measure uptake into Caco-2 cells grown on filters, in the presence of basal leptin at short incubation times (5 and 30 min) and after 6 h of preincubation with the hormone. In order to compare apical and basal leptin effect, Gln and β-Ala uptake was measured in the presence of leptin acting from the apical membrane also in cells grown on filters. Basal leptin (8 mM) inhibited by ~15–30 % the uptake of 0.1 mM Gln and 1 mM β-Ala quickly, after 5 min exposure, and the effect was maintained after long preincubation periods. Apical leptin had the same effect. Moreover, the inhibition was rapidly and completely reversed when leptin was removed from the apical or basolateral medium. These results extend our previous findings and contribute to the vision of leptin as an important hormonal signal for the regulation of intestinal absorption of nutrients. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|