Relationship between Plasma Phosphate and Renal Handling of Phosphate: Studies with Low Phosphate Diet and Nicotinamide
Acute intravenous infusions of phosphate have been used to study the relationship between plasma phosphate concentration and renal phosphate excretion (1 – 10). Animals maintained on a normal intake of phosphorus (0.8 – 1.2%) respond to acute phosphate infusions with phosphate excretions ranging from 60 – 90% of the filtered load (5, 7, 9). The high phosphate excretions are not only the result of increases in tubular load exceeding the reabsorptive capacity, but recent studies indicate that at high plasma phosphate concentrations (induced by prolonged intravenous phosphate infusions) the maximal transport rate actually declines (3, 4, 6, 9–11).
KeywordsNicotinamide Adenine Dinucleotide Phosphate Excretion Renal Phosphate Phosphate Reabsorption Phosphate Diet
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