Effects of methyl mercury in combination with polychlorinated biphenyls and brominated flame retardants on the uptake of glutamate in rat

Regulatory limit values for toxicants are in general determined by the toxicology of the single compounds. However, little is known about their combined effects. Methyl mercury (MeHg), polychlorinated biphenyls (PCBs), and brominated flame retard-ants (BFRs) are dominant contaminants in the environment and food. MeHg is a well known neurotoxicant, especially affecting the developing brain. There is increasing evidence that PCB and BFRs also have neurotoxic effects. An enhanced effect of these toxicants, due to either synergistic or additive effects, would be considered as a risk for the fetal development. Here we studied the combinatorial effects of MeHg in combination with PCB or BFR on the reuptake of glutamate in synaptosomes. To provide the optimal conclusion regarding type of interaction, we have analyzed the data using two mathematical models, the Löewe model of additivity and Bliss ’ model of independent action