High activity of K+-dependent plasmalemmal Na+/Ca2+ exchangers in hippocampal CA1 neurons.
Ca(2+) influx via reversed K(+)-dependent (NCKX) and/or K(+)-independent (NCX) plasmalemmal Na(+)/Ca(2+) exchangers may play a role in neuronal death following global brain ischemia to which CA1 neurons are particularly vulnerable. Therefore, this work tested whether the rates of Ca(2+) influx via reversed NCKX or NCX in cultured rat CA1 neurons differ from those in forebrain neurons (FNs) or cerebellar granule cells (CGCs). The NCKX-mediated Ca(2+) influx was several times more rapid in CA1 neurons than in FNs or CGCs and was not affected by Na(+)/Ca(2+) exchange inhibitors, KB-R7943 or bepridil. NCKX reversal inhibitors are not yet available. Their development would greatly facilitate further testing the role of NCKX in ischemic death of CA1 neurons.
Kiedrowski
Lech
L
The Psychiatric Institute, Departments of Psychiatry and Pharmacology, University of Illinois at Chicago, 1601 W. Taylor St., Chicago, IL 60612, USA. Lkiedr@psych.uicedu
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D002586:Cesium / Q000494:pharmacology; D004622:Embryo, Mammalian; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D005942:Gluconates / Q000494:pharmacology; D006096:Gramicidin / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology*; D017136:Ion Transport / Q000187:drug effects; D008094:Lithium / Q000494:pharmacology; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives* / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D011247:Pregnancy; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D019831:Sodium-Calcium Exchanger / Q000819:agonists / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism*; D013890:Thiourea / Q000031:analogs & derivatives* / Q000494:pharmacology
C101670:2-(2-(4-(4-nitrobenzyloxy)phenyl)ethyl)isothiourea methanesulfonate; D018691:Excitatory Amino Acid Antagonists; D005942:Gluconates; D011810:Quinoxalines; D019831:Sodium-Calcium Exchanger; C051643:N-methylglucamine gluconate; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D006096:Gramicidin; D002586:Cesium; D008536:Meglumine; D008094:Lithium; D012964:Sodium; D013890:Thiourea; D011188:Potassium; D002118:Calcium