Adaptation of phosphate transport to low phosphate diet in renal and intestinal brush border membrane vesicles: influence of sodium and pH.

摘要: The possible role of changes in the sodium (Na) affinity carrier for inorganic phosphate (Pi) adaptation Pi transport to low diet was examined both renal and intestinal brush border membranes vesicles (BBMV) obtained from same animal. This assessed by measuring Na concentration resulting half maximal activation (K 0.5Na) BBMV prepared animals adapted either (LPD) or high (HPD) phosphorus 7 days. TheK 0.5Na not modified dietary Pi, BBMV. LPD increased 1794.8±198.0 296.4±362.0 28.2±3.4 80.5±7.2 pmol/mg 10 s For HPD lowering pH 7.4 6 dramatically increasedK 0.5 As compared 7.4, it enhanced approximately 200% membranes. change with acidic prevented expression at 100 mM concentration. However, saturating concentrations (500 renal, 300 membranes), equally expressed types Hill coefficient analysis indicates a 2:1 stoichiometry isolated animals. ratio medium pH.