Erythrosin B inhibits dopamine transport in rat caudate synaptosomes.
Erythrosin B is a member of a class of fluorescein dyes that are suggested to elicit hyperkinesis when ingested by susceptible children. We found that erythrosin B inhibits dopamine uptake in rat caudate synaptosomes "uncompetitively" in the 10- to 800-micromolar range. Half maximal inhibition of uptake occurred at 45 micromolar. Uncompetitive inhibition denotes a decrease in efficacy of the dopamine membrane transport mechanism with an increase in affinity of dopamine to the carrier. Erythrosin B also decreased nonsaturable binding of dopamine to the synaptosome membrane. The inhibitory action of erythrosin B on dopamine uptake is consistent with the hypothesis that erythrosin B can act as a central excitatory agent able to induce hyperkinetic behavior.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002421:Caudate Nucleus / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D004923:Erythrosine / Q000494:pharmacology*; D005452:Fluoresceins / Q000494:pharmacology*; D007700:Kinetics; D051381:Rats; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D005452:Fluoresceins; D004923:Erythrosine; D004298:Dopamine