The effects of alpha-lactalbumin and whey protein concentrate on alpha-amino acids, calcium and phosphorus levels in blood and gastrointestinal tractof rats

The effects of two dietary proteins on alpha -amino acids, calcium and phos phorus concentrations in plasma, stomach and intestine were investigated in rats trained to consume, in a single two-hour daily meal, diets containing alpha -lactalbumin (alpha 1a) or whey protein concentrate (WPC) for two we eks. The results indicated that the concentrations of calcium and phosphoru s in the gastrointestinal tract and that of alpha -amino acids in portal ve in were not significantly influenced by the nature of diets. The amount of alpha -amino acids in the gastrointestinal tract of rats fed on WPC diet wa s significantly (p<0.001) higher than that of <alpha>-1a group. The levels of insoluble calcium and insoluble phosphorus in the small intestine were s ignificantly (p<0.001) higher in <alpha>-1a group than in WPC group. These results indicated that the kinetics of alpha -amino acids, calcium and phos phorus were differently influenced by the nature of diet ingested, the samp ling time and the sites of sample collections.