title: Differential transition metal uptake and fluorescent probe localization in hippocampal slices.
abstract: Metals are taken up by the combined action of metal transporters and ion channels. In this communication we have measured the uptake of the biologically important transition metals Mn, Fe, Co, Ni, Cu, Zn and Cd by rat and mouse hippocampal slices using the fluorescent probes FluoZin-3 (FZ3) and Newport Green (NPG), introduced by acetoxymethyl ester (AM) loading. The combination of metals and probes is also used to attempt to localize cellular sites into which metals translocate. We show that FZ3 and NPG partition into different cellular compartments; FZ3 into neuropil, whereas NPG localizes in neuropil and compartments within the cell bodies of neurons. Ni, Zn and Cd pass across the plasma membrane and then accumulate in intracellular vesicles and within intracellular membranes of cell bodies. The latter accumulate Cd, while synaptic vesicles take up Co. The passage of Mn, Cu and Fe into cells can be detected but there is some uncertainty about their disposition within the cell. All of our experiments are consistent with metals accumulating in intracellular compartments rather than the cytoplasm. Whether and to what extent there are transient elevations of free zinc levels in the cytoplasm remains unclear.
authors.affiliation: Dept. Biology, 336 BB, University of Iowa, Iowa City, IA 52242, USA. alan-kay@uiowa.edu
authors.forename: Alan R
authors.initials: AR
authors.lastname: Kay
authors.forename: Sean M
authors.initials: SM
authors.lastname: Rumschik
mesh_terms: D000818:Animals; D002614:Chelating Agents / Q000494:pharmacology; D018891:Dentate Gyrus / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D011083:Polycyclic Compounds / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D028561:Transition Elements / Q000378:metabolism*
chemical_list: D002614:Chelating Agents; C451182:FluoZin-3; D005456:Fluorescent Dyes; D011083:Polycyclic Compounds; D028561:Transition Elements