PHOSPHATE-TRANSPORT ACROSS RENAL CORTICAL BRUSH-BORDER MEMBRANE-VESICLES FROM RATS STABILIZED ON A NORMAL, HIGH OR LOW PHOSPHATE DIET

Phosphate uptake measured at 0.25, 0.5 and 1.0 min time intervals was 2-fold higher in renal brush border membrane vesicles from rats fed a low phosphate diet compared to control rats given a normal phosphate diet. In rats on a high phosphate diet the uptake of phosphate at the same time intervals was 2-fold lower compared to controls. D-glucose uptake by the same vesicle preparations was not significantly different between the three groups at 0.25, 0.5 and 1.0 min. At each of these time points there was a positive correlation between phosphate uptake and the activity of alkaline phosphatase which was measured in the vesicle preparations from each group of rats. There was no correlation between phosphate uptake and the activities of three other brush border enzymes. © 1979.