Luminal nutrients alter tight-junction permeability in the rat jejunum: an in vivo perfusion model
| Autor: | D C Sadowski, J B Meddings |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Physiology
Polyethylene glycol Biology Permeability Polyethylene Glycols Rats Sprague-Dawley chemistry.chemical_compound Body Water In vivo Physiology (medical) medicine Animals Fluorometry Intestinal Mucosa Cells Cultured Pharmacology Alanine Tight junction Rhodamines Dextrans General Medicine Small intestine Culture Media Rats Molecular Weight Perfusion Glucose Jejunum Dextran medicine.anatomical_structure Intestinal Absorption chemistry Biochemistry Permeability (electromagnetism) Paracellular transport Biophysics Fluorescein-5-isothiocyanate Intracellular Ferrocyanides |
| Zdroj: | Canadian Journal of Physiology and Pharmacology. 71:835-839 |
| ISSN: | 1205-7541 0008-4212 |
| DOI: | 10.1139/y93-125 |
| Popis: | The regulation of tight-junction permeability between enterocytes has been studied using in vitro perfused loops, Ussing chambers, and cultured cell monolayers. In this communication we demonstrate the ability of an in vivo perfusion model to monitor tight-junction permeability and respond appropriately to physiological luminal stimuli. By using the highly charged anionic ferrocyanide molecule, water flux could be accurately assessed in the rat, and the luminal clearance of high molecular weight dextrans could be used to probe the opening and closing of the paracellular pathway. By utilizing two different molecular weight dextrans markers simultaneously, each conjugated with a different fluorophore, we were able to calculate luminal clearances of these compounds by fluorometric techniques in the presence of luminal nutrients that have previously been demonstrated to open intercellular tight junctions. In the absence of luminal nutrients or the presence of a non-nutrient sugar such as mannitol, clearance of these compounds was negligible. However, with the addition of either D-glucose or L-alanine, clearance of both high molecular weight markers increased dramatically. Thus, opening of tight junctions between enterocytes appears to be a physiological event that occurs in vivo under conditions likely to be found in the lumen. Polyethylene glycol 400 (PEG-400) clearance did not correlate well with the clearance of either dextran marker, suggesting that this probe utilizes a different permeation pathway and may not be appropriate to quantify the nutrient-regulatable pathway observed with the former probes.Key words: intestinal permeability, glucose transport, paracellular transport. |
| Databáze: | OpenAIRE |
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