PT  - JOURNAL ARTICLE
AU  - Frédérique Scamps
AU  - Stéphan Vigues
AU  - Sophie Restituito
AU  - Brice Campo
AU  - Anne Roig
AU  - Pierre Charnet
AU  - Jean Valmier
TI  - Sarco-Endoplasmic ATPase Blocker 2,5-Di(&lt;em&gt;tert&lt;/em&gt;-butyl)-1,4-benzohydroquinone Inhibits N-, P-, and Q- but Not T-, L-, or R-Type Calcium Currents in Central and Peripheral Neurons
AID  - 10.1124/mol.58.1.18
DP  - 2000 Jul 01
TA  - Molecular Pharmacology
PG  - 18--26
VI  - 58
IP  - 1
4099  - http://molpharm.aspetjournals.org/content/58/1/18.short
4100  - http://molpharm.aspetjournals.org/content/58/1/18.full
SO  - Mol Pharmacol2000 Jul 01; 58
AB  - The effects of 2,5-di(tert-butyl)-1,4-benzohydroquinone (tBHQ), a synthetic phenolic antioxidant and a blocker of the sarco-endoplasmic ATPase, were evaluated on low and high voltage-activated Ca2+ currents (ICas) with rodent dorsal root ganglion, hippocampal, and motor neurons. In all cell types tested, tBHQ (IC50 = 35 μM) blocked ICa at concentrations used to inhibit sarco-endoplasmic ATPase. This effect was specific to tBHQ because the other sarco-endoplasmic reticulum calcium ATPase pump inhibitors (thapsigargin and cyclopiazonic acid) had no effect. Selective blockade of the N-type current with ω-conotoxin GVIA and of P- (motoneuron) or Q-type currents (hippocampal neuron) with ω-agatoxin IVA indicated that tBHQ inhibited N, P, and Q types of ICa. tBHQ had no effect on nitrendipine-sensitive (L-type) and residual drug-resistant (R-type) ICa, nor on the low voltage-activated T-type ICa. Contrary to neuronal cells, the L-type ICa was inhibited by tBHQ in a differentiated mouse neuroblastoma and rat glioma hybrid cell line. Injection of cDNAs encoding the α1A, α1B, α1C, and α1E subunits into oocytes showed that tBHQ blocked ICas at the level of the pore-forming protein. This effect of tBHQ on ICa should be considered when interpreting results obtained with tBHQ used on neuronal preparations. It also may be useful for developing new strategies for the generation of more potent intracellular calcium transient inhibitors.