Role of capacitative calcium entry on glutamate-induced calcium influx in type-I rat cortical astrocytes.
Capacitative calcium entry (CCE) has been described in a variety of cell types. To date, little is known about its role in the CNS, and in particular in the cross-talk between glia and neurons. We have first analyzed the properties of CCE of astrocytes in culture, in comparison with that of the rat basophilic leukemia cell line (RBL-2H3), a model where calcium release-activated Ca2+ (CRAC) channels have been unambiguously correlated with CCE. We here show that (i) in astrocytes CCE activated by store depletion and Ca2+ influx induced by glutamate share the same pharmacological profile of CCE in RBL-2H3 cells and (ii) glutamate-induced Ca2+ influx in astrocytes plays a primary role in glutamate-dependent intracellular Ca2+ concentration ([Ca2+]i) oscillations, being these latter reduced in frequency and amplitude by micromolar concentrations of La3+. Finally, we compared the expression of various mammalian transient receptor potential genes (TRP) in astrocytes and RBL-2H3 cells. Despite the similar pharmacological properties of CCE in these cells, the pattern of TRP expression is very different. The involvement of CCE and TRPs in glutamate dependent activation of astrocytes is discussed.
Pizzo
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P
Department of Biomedical Sciences and the National Research Council Center for the Study of Biomembranes, University of Padua, Padua, Italy.
Burgo
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A
Pozzan
T
T
Fasolato
C
C
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000235:genetics; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology*; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005456:Fluorescent Dyes; D018698:Glutamic Acid / Q000494:pharmacology*; D007211:Indoles / Q000494:pharmacology; D007811:Lanthanum / Q000494:pharmacology; D015471:Leukemia, Basophilic, Acute; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050052:TRPC Cation Channels; D019284:Thapsigargin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D015220:Calcium Channels; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D007211:Indoles; D012333:RNA, Messenger; D050052:TRPC Cation Channels; D018698:Glutamic Acid; D004533:Egtazic Acid; D019284:Thapsigargin; D007811:Lanthanum; D000252:Calcium-Transporting ATPases; C048960:indo-1; D002118:Calcium; C000543:cyclopiazonic acid