Fig. 3.
Effects of dietary Pi on intestinal and renal BBMV Pi transport activity. Na-Pi transporter uptake was measured in BBMV of duodenum (A) and jejunum (B) of rats chronically fed high-Pi (1.2%), normal-Pi (0.6%), or low-Pi (0.1%) diet. Pi uptake in BBMV from jejunum was increased 67% in rats fed the low-Pi diet compared with rats fed the high-Pi diet (59.6 ± 14.2, 46.3 ± 11.4, and 123.9 ± 14.3 pmol Pi·mg protein−1·30 s−1 for rats fed 1.2%, 0.6%, and 0.1% Pi, respectively). No significant regulation is observed in BBMV from duodenum. C: progressive upregulation of phosphate uptake in BBMV isolated from kidney superficial cortex (SC-BBMV) in rats fed normal-Pi and low-Pi diet compared with rats fed high-Pi diet. *P < 0.05. **P < 0.01. ***P < 0.001.