Prediction of cadmium (Cd) toxicity in cattle

Abstract

Hepato- and nephrotoxicity can be induced by the exposure to cadmium (Cd). This toxicity can be detected by the elevation of blood biomarkers such as ALT, AST, ALP, BUN and creatinine. These elevations are found in small animals, e.g. mice and rats. However, the alteration of biomarkers did not investigate in large animals, e.g. cattle. Hepato- and nephrotoxicity induced by cadmium can also be examined by the alterations of metallothionein (MT) and metal transcription factor-1 (MTF-1). To present study the expressions of these markers, the cattle were classified into five groups according to the levels of cadmium in the kidneys. ALT, AST and ALP were analyzed to determine liver damage whereas BUN and creatinine were examined for kidney damage. The results showed that blood biomarkers were not sensitive enough to be correlated markers to cadmium induced hepato- and nephrotoxicity in cattle. The expressions of MT and MTF-1 protein were investigated by immunofluorescence method. The expressions of MT and MTF-1 proteins were firstly found in the cattle group which had low cadmium concentration in tissues ( < 0.5 mg/kg). Thus, these proteins could be used as the sensitive markers to determine the cadmium exposure. The MT and MTF-1 gene expressions were also studied. However, there was no correlation between the level of RNA and the protein expressions due to the concentration of protein levels bearing unclear relationship with the mRNA level. The investigation of these protein expressions is very useful because the result can be used as a protective method to prevent consumption of cadmiumcontaminated beef.