Document Detail

Volatile anesthetics increase intracellular calcium in cerebrocortical and hippocampal neurons.
MedLine Citation:
PMID:  10201687     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: An increase in intracellular calcium concentration ([Ca2+]i) in neurons has been proposed as an important effect of volatile anesthetics, because they alter signaling pathways that influence neurotransmission. However, the existing data for anesthetic-induced increases in [Ca2+]i conflict. METHODS: Changes in [Ca2+]i were measured using fura-2 fluorescence spectroscopy in rat cortical brain slices at 90, 185, 370, and 705 microM isoflurane. To define the causes of an increase in [Ca2+]i, slices were studied in Ca2+-free medium, in the presence of Ca2+-channel blockers, and in the presence of the Ca2+-release inhibitor azumolene. The authors compared the effect of the volatile anesthetic with that of the nonanesthetic compound 1,2-dichlorohexafluorocyclobutane. Single-dose experiments in CA1 neurons in hippocampal slices with halothane (360 microM) and in acutely dissociated CA1 neurons with halothane (360 microM) and isoflurane (445 microM) also were performed. RESULTS: Isoflurane at 0.5, 1, and 2 minimum alveolar concentrations increased basal [Ca2+]i in cortical slices in a dose-dependent manner (P < 0.05). This increase was not altered by Ca2+-channel blockers or Ca2+-free medium but was reduced 85% by azumolene. The nonanesthetic 1,2-dichlorohexafluorocyclobutane did not increase [Ca2+]i. In dissociated CA1 neurons, isoflurane reversibly increased basal [Ca2+]i by 15 nM (P < 0.05). Halothane increased [Ca2+]i in dissociated CA1 neurons and CA1 neurons in hippocampal slices by approximately 30 nM (P < 0.05). CONCLUSIONS: (1) Isoflurane and halothane reversibly increase [Ca2+]i in isolated neurons and in neurons within brain slices. (2) The increase in [Ca2+]i is caused primarily by release from intracellular stores. (3) Increases in [Ca2+]i occur with anesthetics but not with the nonanesthetic 1,2-dichlorohexafluorocyclobutane.
C H Kindler; H Eilers; P Donohoe; S Ozer; P E Bickler
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Anesthesiology     Volume:  90     ISSN:  0003-3022     ISO Abbreviation:  Anesthesiology     Publication Date:  1999 Apr 
Date Detail:
Created Date:  1999-04-21     Completed Date:  1999-04-21     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  1300217     Medline TA:  Anesthesiology     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1137-45     Citation Subset:  AIM; IM    
Department of Anesthesia, University of California, San Francisco 94143-0542, USA.
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MeSH Terms
Anesthetics, Inhalation / pharmacology*
Calcium / metabolism*
Cerebral Cortex / drug effects*,  metabolism
Halothane / pharmacology*
Hippocampus / drug effects*,  metabolism
Isoflurane / pharmacology*
Rats, Sprague-Dawley
Grant Support
Reg. No./Substance:
0/Anesthetics, Inhalation; 151-67-7/Halothane; 26675-46-7/Isoflurane; 7440-70-2/Calcium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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