Effect of the chelate action of sodium citrate on calcium metabolism in rats

Abstract

Influence of the Chelate Action of the Sodium Citrate on the Calcium Metabolism in Rats

A study is made in rats of the influence of the addition of sodium oxalate and of sodium citrate to the diet on the metabo­ lism of calcium.

In the calcium balance experiments, using the method of Thomas-Mitchell, lots of 10 adult rats were employed, in individual metabolism cages which allowed the control and collection of ingesta, urine and faeces. Each experiment lasted ten days, three to adapt the animal and seven to control ingesta, faeces and urine. The apparent and true digestibility coefficient, biological value and net availablecalcium were determined by analysis of calcium in the diet and excreta. Determination fecal and urine elimination of endogenous calcium was carried out individually for each of the animals comprising each lot, using a synthetic diet without calcium.

Our experiments lead to the following conclusions:

Sodium oxalate decreases the apparent and true digestibility coefficient of cal­cium. It increases the retention of calcium absorbed. It also appears to decrease the urine elimination of endogenous calcium.

Sodium citrate increases the digestibility of calcium, when this is decreased by the presence of sodium oxalate in the diet. The retention of calcium absorbed is de­ creased by the action of sodium citrate.