[Effects of oxiracetam on the decrease in population spikes in hypoxic and low glucose media].
Evoked potentials were recorded in rat cerebral cortical slices. The amplitude of the evoked potential was reduced by perfusion with hypoxic (0-25%) or low glucose (0-5 mM) media in a concentration-dependent manner, and the evoked potentials disappeared under severe conditions (below 15% O2, below 3 mM glucose). We investigated the protective effects of oxiracetam on the decrease in evoked potentials under hypoxic (15% O2) and low glucose (3 mM glucose) conditions. Drugs were perfused from 45 min before hypoxic or low glucose perfusion to the end of the experiment. Oxiracetam (10(-6)-10(-5) M) dose-dependently minimized the amplitude reduction of evoked potentials and prolonged their disappearance time. At a concentration of 10(-5) M, oxiracetam protected against the disappearance of evoked potential in 5 of the 6 samples under hypoxic conditions and in all 6 samples under low glucose conditions. Indeloxazine (5 x 10(-6)-10(-5) M) and bifemelane (5 x 10(-6)-10(-5) M) prevented the reduction of the amplitude of evoked potentials under low glucose conditions. However, these drugs had no effect at a concentration of 10(-6) M. These data indicate that oxiracetam has a protective effect against neuronal dysfunction and that this effect develops at a lower concentration than those of indeloxazine and bifemelane.
Hokonohara
T
T
Research Laboratories TOYO JOZO Co., Ltd., Shizuoka, Japan.
Shinoda
Y
Y
Hori
N
N
D000818:Animals; D001559:Benzhydryl Compounds / Q000494:pharmacology; D002540:Cerebral Cortex / Q000187:drug effects* / Q000503:physiopathology; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology; D005947:Glucose / Q000378:metabolism*; D002534:Hypoxia, Brain / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D009025:Morpholines / Q000494:pharmacology; D010477:Perfusion; D011619:Psychotropic Drugs / Q000494:pharmacology*; D011759:Pyrrolidines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D001559:Benzhydryl Compounds; D009025:Morpholines; D011619:Psychotropic Drugs; D011759:Pyrrolidines; C020852:indeloxazine; D005947:Glucose; C040619:oxiracetam; C031906:bifemelane