Screening of the toxic effects of a high melamine dose on the biochemical hematological and histopathological investigations in male rats.

Screening of the toxic effect of a high oral melamine dose (30,000 ppm supplemented in the diet) was performed for 28 days on male rats. The morphology, anatomy, complete blood count (CBC), serum electrolytes, kidney function, serum proteins, serum bilirubin, serum liver enzymes, catalase, glutathion-S-transferase, lipid peroxide, serum melamine concentration, total body weight, food intake, food efficiency ratio (FER), body weight gain percentage (BWG%), body weight gain, water consumption, and histopathological examinations of kidney, urinary bladder, testis, liver, heart, and spleen were investigated. The melamine-supplemented rats turned yellow and showed different degrees of hypertrophy and congestion, particularly the kidney and the ureter as a result of melamine toxicity. The CBC showed minimal changes in the melamine-supplemented groups. Na and Cl were decreased, whereas K, P, and Ca were increased. Serum creatinine, uric acid, and urea were elevated. Liver function enzymes were nonsignificantly affected. Catalase and glutathion-S-transferase were decreased, whereas lipid peroxide was increased in the kidney tissue homogenate. It was also noted that serum protein was decreased and serum bilirubin was increased. Histopathologically, most examined organs were severely injured specially the kidneys, liver, and testes.