FCCP releases Ca2+ from a non-mitochondrial store in an identified Helisoma neuron.
The proton ionophore FCCP was evaluated for use as a selective blocker of mitochondrial Ca2+ sequestration in identified Helisoma neurons in vitro. By use of the Ca2+ indicator fura-2, it was found that application of FCCP evoked a gradual increase in cell body [Ca2+]i that reached a level approximately 3-fold higher than baseline after 60 min. Moreover, FCCP released Ca2+ even when added after mitochondrial stores of Ca2+ had previously been emptied by an alternate method. From these and other experiments, it is concluded that FCCP, in addition to its recognized effect on mitochondrial Ca2+ sequestration, also releases Ca2+ from a non-mitochondrial store and is, therefore, unsuitable for use in an intact neuron to selectively inactivate mitochondrial Ca2+ uptake.
Jensen
J R
JR
Department of Anatomy and Neurobiology, Colorado State University, Fort Collins 80523.
Rehder
V
V
D000818:Animals; D000968:Antimycin A / Q000031:analogs & derivatives / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology*; D008928:Mitochondria / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D009840:Oligomycins / Q000494:pharmacology; D009994:Osmolar Concentration; D012402:Rotenone / Q000494:pharmacology; D012908:Snails
D009840:Oligomycins; D012402:Rotenone; C032456:antimycin; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D000968:Antimycin A; D002118:Calcium