Effects of extracellular Ca(2+) influx and intracellular Ca(2+) release on ethanol-induced cytoplasmic Ca(2+) overload in cultured superior cervical ganglion neurons.
The present research was designed to investigate the interference of Ca(2+) homeostasis by ethanol on the primary cultured superior cervical ganglion (SCG) neurons. (1) Using the whole cell patch clamp recording, the amplitudes of voltage-dependent Ca(2+) channel (VDCC) currents could be reduced by ethanol in a concentration-dependent manner. Ethanol (100mM) inhibited about 25% of Ca(2+) channel current. However, the activation of Ca(2+) channel was not affected by ethanol at those concentrations. (2) The similar extent inhibitions of 100mM ethanol on the increments of intracellular Ca(2+) concentration ([Ca(2+)](i)) induced by 40 mM KCl and 1 microM A23187 were also observed in the fluo-3-AM loaded superior cervical ganglia (SCG) via detecting the change of [Ca(2+)](i) with a laser scanning confocal microscopy. In contrast, the basal [Ca(2+)](i) was significantly increased by ethanol alone in a concentration-dependent manner. These phenomena were also observed even under Ca(2+) free bath solution or the solution added 300 microM cadmium chloride conditions. Together with above results, our data suggest that ethanol increases basal [Ca(2+)](i), but it also inhibits the extracellular Ca(2+) influx through VDCC and ionophore channel. And the augment of basal [Ca(2+)](i) induced by ethanol might attribute to the Ca(2+) releasing from intracellular Ca(2+) pools.
Xiao
Zhe-Man
ZM
Department of Neurology, Institution of Neuropsychiatry Research, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, PR China. xiaotekko@yahoo.com.cn
Li
Li-Jun
LJ
Yu
Shao-Zu
SZ
Lu
Zu-Neng
ZN
Li
Chen-Yan
CY
Zheng
Jian-Quan
JQ
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D006706:Homeostasis; D008297:Male; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D017783:Superior Cervical Ganglion / Q000166:cytology*
D015220:Calcium Channels; D000431:Ethanol; D002118:Calcium