Evidence for an extracellular zinc-veneer in rodent brains from experiments with Zn-ionophores and ZnT3 knockouts.
Ionic zinc is found at a high concentration in some glutamatergic vesicles of the mammalian brain. Ionic zinc is also found chelated to macromolecules in the extracellular space, constituting what has been called the "zinc veneer". In this communication we show that the zinc ionophore, pyrithione, can be used to demonstrate the presence of the veneer. Application of pyrithione without added ionic zinc to rodent hippocampal slices mobilizes extracellular zinc, which can be detected intracellularly by the zinc probe FluoZin-3. In addition, we show that ZnT3 null mice, which lack the transporter responsible for stocking synaptic vesicles, nevertheless do have a zinc veneer, albeit diminished compared to wild type animals. The presence of the zinc veneer in ZnT3 null mice may account for the absence of any marked deficit in these animals.
Department of Chemistry, 336 BB, University of Iowa, Iowa City, Iowa 52242, USA.
Irma
I
Nydegger
Sean M
SM
Rumschik
Jinfu
J
Zhao
Alan R
AR
Kay
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002352:Carrier Proteins / Q000032:analysis; D027682:Cation Transport Proteins; D045604:Extracellular Fluid / Q000378:metabolism*; D007476:Ionophores / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000032:analysis / Q000172:deficiency*; D026901:Membrane Transport Proteins; D051379:Mice; D018345:Mice, Knockout; D009924:Organ Culture Techniques; D011083:Polycyclic Compounds / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015032:Zinc / Q000032:analysis / Q000378:metabolism*
D002352:Carrier Proteins; D027682:Cation Transport Proteins; C451182:FluoZin-3; D007476:Ionophores; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D011083:Polycyclic Compounds; C491177:Slc30a3 protein, mouse; D015032:Zinc