Species differences in functions of dopamine transporter: Paucity of MPP(+) uptake and cocaine binding in bovine dopamine transporter

Expression of cloned cDNA for human, rat and bovine dopamine transporter (DAT) in COS cells allows the comparison of the functional differences among the respective dopamine transporters. Human DAT showed the highest activities for dopamine uptake, MPP(+) uptake and cocaine binding, indicating that humans are more vulnerable to 1-methyl-4-phenylpyridinium (MPP(+)) toxicity and cocaine addiction. However, bovine DAT showed poor MPP(+) uptake and cocaine binding, even though its dopamine uptake ability was quite avid. Here, we conclude that the paucity of MPP(+) uptake and cocaine binding is a unique characteristic in bovine DAT.