Helium-oxygen pressure induces striatal glutamate increase: a microdialysis study in freely-moving rats.
In rat, helium pressures induce locomotor and motor activity which requires dopaminergic and N-methyl-D-aspartate (NMDA) receptor activities at striatal level. However, biochemical studies have suggested that pressure exposure may increase striatal glutamate level. We used microdialysis technique to study the effects of pressure on glutamate level in the striatum and the effects of local administration of D1 (SCH23390) or D2 (sulpiride) on these changes. Pressures increase both glutamate and glutamine levels in striatal microdialysates. Administration of sulpiride (1 microM) or SCH23390 (1 microM) by reverse microdialysis did not affect significantly pressure induced glutamate increase. So, protective effects of D1 and D2 antagonists against locomotor and motor hyperactivity (LMA) are probably independent of the processes involved in the striatal glutamate increase evoked by pressure.
Darbin
O
O
Laboratoire de Physiopathologie et Action Thérapeutique des Gaz Sous Pression, Université de la Méditerranée et IMNSSA, Institut J. Roche, Faculté de Médecine Nord, 13916 Cedex 20, Marseille, France.
Risso
J J
JJ
Rostain
J C
JC
D000818:Animals; D001274:Atmospheric Pressure; D001552:Benzazepines / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D018492:Dopamine Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000187:drug effects* / Q000378:metabolism; D005973:Glutamine / Q000187:drug effects* / Q000378:metabolism; D006371:Helium / Q000494:pharmacology*; D006610:High Pressure Neurological Syndrome / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D017551:Microdialysis; D009043:Motor Activity; D010100:Oxygen / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013469:Sulpiride / Q000494:pharmacology
D001552:Benzazepines; D018492:Dopamine Antagonists; D005973:Glutamine; D006371:Helium; D018698:Glutamic Acid; D013469:Sulpiride; D010100:Oxygen