Effects of pH and Sodium on Phosphate Transport Across Brush Border Membrane Vesicles of Small Intestine
It is known that, in isolated intact rat small intestine, the phosphate (Pi) transport from lumen to tissue increases when the pH of the luminal solution is reduced1. A similar observation has also been reported in brush border membrane vesicles (BBMV) from rat small intestine2. These results have suggested that the increase in mono- respective to divalent phosphate, which occurs when pH is reduced, was responsible for the higher uptake found at acidic pH, thus leading to the conclusion that primary Pi was transported across the brush border of small intestinal epithelium. Such a conclusion, however, is valid only if direct effects of pH on the phosphate transport system are excluded.
KeywordsBrush Border Membrane Phosphate Transport Phosphate Uptake Brush Border Membrane Vesicle Rabbit Small Intestine
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