NMDA receptor activation enhances diazepam binding inhibitor and its mRNA expressions in mouse cerebral cortical neurons.
Effects of N-methyl-D-aspartate (NMDA) on diazepam binding inhibitor (DBI) and its mRNA expression in mouse cerebral cortical neurons were examined. A significant increase in DBI mRNA expression was observed 1 day after the exposure to 0.1 microM NMDA and the maximal expression occurred 2 days after the exposure, whereas transient exposure to 0.1 microM NMDA for 15 min, 1 and 3 h produced no changes in the expression. Similarly, no changes in the expression were found by the concomitant exposure to NMDA and MK-801, a NMDA receptor antagonist, for 72 h subsequent to the incubation with NMDA alone for 3 h. Such NMDA-induced increases in DBI mRNA expression were dose-dependently inhibited by MK-801. Moreover, neuronal DBI content significantly increased by treatment with NMDA, which was completely abolished by MK-801. These results indicate that continuous activation of NMDA receptors is an essential factor for increasing DBI expression in the neurons.
Katsura
M
M
Department of Pharmacology, Kawasaki Medical School, Matsushima, Kurashiki 701-0192, Japan.
Takesue
M
M
Shuto
K
K
Mohri
Y
Y
Tarumi
C
C
Tsujimura
A
A
Shirotani
K
K
Ohkuma
S
S
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002540:Cerebral Cortex / Q000166:cytology*; D026261:Diazepam Binding Inhibitor; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D051379:Mice; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
D002352:Carrier Proteins; D026261:Diazepam Binding Inhibitor; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate