Thiopental and isoflurane attenuate the decrease in hippocampal phosphorylated Focal Adhesion Kinase (pp125FAK) content induced by oxygen-glucose deprivation.
BACKGROUND
Thiopental and isoflurane exhibit neuroprotective effects against cerebral ischaemia. Here, we hypothesized that oxygen-glucose deprivation decreases the ATP-dependent phosphorylation process of Focal Adhesion Kinase (pp125FAK, a functionally important non-receptor tyrosine kinase), and that this phenomenon is attenuated by thiopental and isoflurane.


METHODS
Rathippocampal slices were subjected to an anoxic-aglycaemic (or physiologic, control) challenge followed by 3-h reperfusion, and treated with various concentrations of thiopental and isoflurane. PP125FAK phosphorylation was measured by immunoblotting. Neuronal death was assessed by immunostaining with bis-benzimide.


RESULTS
Significant neuronal death was detected after 30 min (but not 10) of anoxia-aglycaemia (40 (4) vs 14 (5)% of control, P<0.05). At 30 min, phosphorylated pp125FAK content was significantly decreased by anoxic glucose-free conditions (55 (27)% of control, P<0.05). This effect was markedly attenuated by thiopental (10 and 100 microM) and isoflurane (1 and 2%). Under control conditions, thiopental (1, 10, and 100 microM) and isoflurane (0.5, 1, and 2%) increased pp125FAK phosphorylation in a concentration-related fashion. This effect was blocked by chelerythrin and bisindolylmaleimide I and IX (10 microM, three structurally distinct inhibitors of protein kinase C, PKC) but not the N-methyl-D-aspartate (NMDA) receptor antagonist MK801 (10 microM).


CONCLUSIONS
Phosphorylated pp125FAK content was markedly decreased in hippocampal slices subjected to oxygen-glucose deprivation. Thiopental and isoflurane significantly attenuated this phenomenon, possibly via PKC activation.
Dahmani
S
S
Department of Anaesthesia, Bichat University Hospital, 46 rue Henri Huchard, F-75018 Paris, France.
Tesnière
A
A
Rouelle
D
D
Desmonts
J-M
JM
Mantz
J
J
D000255:Adenosine Triphosphate / Q000502:physiology; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D000818:Animals; D015687:Cell Hypoxia / Q000502:physiology; D046508:Culture Techniques; D004305:Dose-Response Relationship, Drug; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D005947:Glucose / Q000172:deficiency; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology; D007530:Isoflurane / Q000494:pharmacology*; D008297:Male; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013874:Thiopental / Q000494:pharmacology*
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D000255:Adenosine Triphosphate; D007530:Isoflurane; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496052:Ptk2 protein, rat; D005947:Glucose; D013874:Thiopental