Mechanisms and kinetics of α-linolenic acid uptake in Caco-2 clone TC7
| Autor: | Thierry Tranchant, Jacques Goré, Pierre Besson, Claude Hoinard, Jacques Delarue, Jean Michel Antoine, Charles Couet |
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| Rok vydání: | 1997 |
| Předmět: |
Time Factors
Antimetabolites Linolenic acid Sodium Population Biophysics chemistry.chemical_element Adenocarcinoma Deoxyglucose Biochemistry Substrate Specificity chemistry.chemical_compound Endocrinology Essential fatty acid Humans Carbon Radioisotopes Enzyme Inhibitors Intestinal Mucosa Monensin education chemistry.chemical_classification education.field_of_study Chromatography Ionophores biology Membrane transport protein alpha-Linolenic acid Fatty Acids Osmolar Concentration Serine Endopeptidases Temperature alpha-Linolenic Acid Fatty acid Lipids Clone Cells Intestines Kinetics Glucose chemistry Caco-2 Colonic Neoplasms biology.protein Oligomycins Caco-2 Cells Cell Division |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 1345:151-161 |
| ISSN: | 0005-2760 |
| DOI: | 10.1016/s0005-2760(96)00171-3 |
| Popis: | The uptake kinetics of alpha-linolenic acid (18:3(n - 3)), an essential fatty acid, were investigated in the human intestinal cell line Caco-2. Four clones (PD10, PF11, PD7 and TC7) from the heterogeneous parental Caco-2 cells population were used. After a screening step using isolated cells, the TC7 clone was selected for the study of alpha-linolenic acid uptake. [1-(14)C]linolenic acid dissolved in 10 mM taurocholate was presented to the microvillus plasma membrane (apical side) of TC7 differentiated cells, grown on a semi-permeable polycarbonate membrane. The results show that the initial rate of uptake is not a linear function of the 18:3(n- 3) monomer concentration in the incubation medium. In the monomer concentration range studied (0.2 to 36 microM) apical uptake was saturable and followed Michaelis-Menten kinetics (V(max) = 15.4 +/- 0.6 nmol/mg protein per min, K(m) = 14.3 +/- 1.3 microM). In addition, it was temperature- and energy-dependent but was apparently unaffected by the sodium gradient and intracellular metabolic fate of 18:3(n - 3). Excess of unlabeled saturated or unsaturated long chain fatty acids (C16 to C22) led to a 27-68% reduction of [1-(14)C]linolenic acid uptake. Likewise basolateral uptake was saturable (V(max) = 4.9 +/- 0.7 nmol/mg protein per min, K(m) = 8.7 +/- 2.9 microM). These facts argue in favour of the existence in these human intestinal cells of a carrier-mediated transport system for alpha-linolenic acid and probably other long chain fatty acids as well. |
| Databáze: | OpenAIRE |
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