Early anesthetic preconditioning in mixed cortical neuronal-glial cell cultures subjected to oxygen-glucose deprivation: the role of adenosine triphosphate dependent potassium channels and reactive oxygen species in sevoflurane-induced neuroprotection.
BACKGROUND
The purpose of the present study, on mixed cortical neuronal-glial cell cultures subjected to transient oxygen-glucose deprivation (OGD) was: i) to compare the neuroprotection afforded by sevoflurane added either before (preconditioning) or during (direct neuroprotection) the OGD and ii) to explore the possible involvement of adenosine triphosphate-sensitive potassium (KATP) channels and intracellular reactive oxygen species (ROS) levels in the mechanism of the early preconditioning effect of sevoflurane.


METHODS
Mature mixed cortical neuronal-glial cell cultures were exposed to 90-min OGD in an anaerobic chamber followed by reoxygenation. Sevoflurane (0.03-3.4 mM) was randomly administered for 90 min and discontinued 60 min before OGD (early preconditioning) or during the 90-min OGD (direct neuroprotection). Cell death was quantified 24 h after the OGD by lactate dehydrogenase release into the bathing medium. Intracellular ROS generation was assessed at the end of sevoflurane preconditioning using 2',7'-dichlorofluorescin diacetate.


RESULTS
Sevoflurane preconditioning elicited a potent threshold-dependent neuroprotective effect at concentrations higher than 0.07 mM and sevoflurane added during OGD elicited a dose dependent neuroprotective effect. Blockers of KATP channels (glibenclamide 0.3 microM and 5 hydroxydecanoic acid 50 microM), or ROS-scavengers (N-2-mercaptopropionyl glycine 100 microM and N-acetylcysteine 50 microM), although they did not affect cell viability, counteracted the neuroprotection produced by early sevoflurane preconditioning. Sevoflurane exposure during preconditioning induced a significant increase in ROS levels which was prevented by both ROS scavengers and blockers of KATP channels.


CONCLUSIONS
Early sevoflurane preconditioning induced a threshold-dependent protection of mixed cortical neuronal-glial cell cultures against OGD by mechanisms that seem to involve opening KATP channels, thereby leading to generation of ROS.
Velly
Lionel J
LJ
Department of Anesthesia, Centre Hospitalier Universitaire Timone Adultes, Marseille, France. lionel.velly@ap-hm.fr
Canas
Paula T
PT
Guillet
Benjamin A
BA
Labrande
Christelle N
CN
Masmejean
Frédérique M
FM
Nieoullon
André L
AL
Gouin
François M
FM
Bruder
Nicolas J
NJ
Pisano
Pascale S
PS
D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D016923:Cell Death / Q000187:drug effects; D015687:Cell Hypoxia / Q000187:drug effects* / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology* / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D005947:Glucose / Q000172:deficiency*; D054086:KATP Channels / Q000187:drug effects / Q000502:physiology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008738:Methyl Ethers / Q000494:pharmacology*; D008858:Microscopy, Phase-Contrast; D009457:Neuroglia / Q000187:drug effects*; D018696:Neuroprotective Agents; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D054086:KATP Channels; D008738:Methyl Ethers; D018696:Neuroprotective Agents; D017382:Reactive Oxygen Species; D000077149:Sevoflurane; D007770:L-Lactate Dehydrogenase; D005947:Glucose