Hexose transport in the apical and basolateral membranes of enterocytes in chickens adapted to high and low NaCl intakes.
1. The effect of a low-NaCl diet (LS diet) on the properties of hexose transport across the brush-border and basolateral membranes of enterocytes from jejunum, ileum and rectum of the chicken was investigated. 2. In the brush-border membrane, LS adaptation had no effect on Km for alpha-methyl-D-glucoside while Vmax values were significantly reduced in the ileum and in the rectum. All Scatchard plots of specific [3H]phlorizin binding give a straight line, consistent with a single population of binding sites. Phlorizin binding vs. alpha-methyl-D-glucoside maximal transport rates showed a linear correlation. 3. In the basolateral membrane, the LS diet did not modify the Km for D-glucose but reduced the Vmax in the ileum and in the rectum. Scatchard plots of [3H]cytochalasin B binding support the view that there is a single transport system in this membrane. There was a linear correlation between cytochalasin B binding and D-glucose Vmax values. 4. The response of the chicken intestine to LS intake consists of a dramatic reduction in the number of glucose transporters in both apical and basolateral membranes of the rectum, an intermediate response in the ileum and no significant effects in the jejunum.
Garriga
C
C
Departament de Fisiologia-Divisio IV, Facultat de Farmàcia, Universitat de Barcelona, E-08028, Barcelona,, Spain.
Moretó
M
M
Planas
J M
JM
D019325:3-O-Methylglucose / Q000494:pharmacology; D000450:Aldosterone / Q000097:blood; D000818:Animals; D001485:Basement Membrane / Q000737:chemistry / Q000201:enzymology; D001692:Biological Transport / Q000502:physiology; D002645:Chickens; D003571:Cytochalasin B / Q000494:pharmacology; D003594:Cytoplasmic Granules / Q000201:enzymology; D004039:Diet, Sodium-Restricted; D005947:Glucose / Q000493:pharmacokinetics*; D007082:Ileum / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D007408:Intestinal Absorption / Q000502:physiology; D007583:Jejunum / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D010695:Phlorhizin / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding / Q000502:physiology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012007:Rectum / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D012965:Sodium Chloride / Q000493:pharmacokinetics*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013393:Sucrase / Q000378:metabolism; D014316:Tritium
D009004:Monosaccharide Transport Proteins; D011500:Protein Synthesis Inhibitors; D014316:Tritium; D019325:3-O-Methylglucose; D003571:Cytochalasin B; D012965:Sodium Chloride; D000450:Aldosterone; D010695:Phlorhizin; D013393:Sucrase; D000254:Sodium-Potassium-Exchanging ATPase; D005947:Glucose