Dietary Dried Egg White Protein Influences Accumulation and Distribution of Cadmium in Rats

Abstract

The effect of a dried egg white dietary supplement (2%) on cadmium distribution was examined within 32 d post dosing in the carcass, liver, kidneys, testes, and thigh muscles of male Wistar rats administered cadmium chloride daily, orally for 28 d at a dose corresponding to 10 mg/Cd/kg of feed. Rats fed the egg white protein-supplemented diet displayed markedly higher carcass Cd retention than animals given a standard diet. Further, the protein-supplemented diet increased significantly hepatic Cd retention at 12 h and 4 d, and renal metal retention at 12 h until d 16. In contrast, testicular and thigh-muscle Cd retention was significantly lower in the rats fed the egg white protein supplemented diet compared to rats on a standard diet. Higher carcass, hepatic, and renal Cd concentrations were accompanied by greater body weight gains. Taken together, the results of this study showed that increased egg white dietary protein levels enhanced Cd retention in carcass, liver, and kidneys but lowered the metal concentrations in thigh muscles and testes. Data indicate that body weight gains in rats supplemented with egg white proteins exerted tissue-specific effects with respect to Cd accumulation. The potential toxic risk of Cd burden in testes was diminished due to lower metal levels in rats on a protein-supplemented diet. However, this may not be the case in liver and kidneys, as Cd concentrations rose in presence of protein supplementation.