Glial Peripheral Benzodiazepine Receptor Mediates the Relief of Acute Stress-Induced Anxiety in Rats / 신경정신의학

ABSTRACT

OBJECTIVES: Peripheral benzodiazepine receptor has been suggested to be associated with the relief of anxiety response induced by stresses. This study was designed to observe the anxiolytic activity of peripheral benzodiazepine receptor. METHODS: Male Sprague-Dawley rats, weighing 200-250g were forced to suffer an immobilization stress for 2 hours. The level of anxiety by immobilization was performed by an elevated plus maze and was evaluated by the number of [3H]Ro5-4864 binding sites in the olfactory bulb. RESULTS: Saturation experiments followed by scatchard anlayses of the results showed that the density of peripheral benzodiazepine receptor increased and the affinity of the peripheral benzodiazepine receptor remained unchanged. It was found that there was no significant change in the cerebral cortex. Pretreatment with clonazepam, a central benzodiazepine receptor agonist, before an immobilization stress abolished the anxoius response on the performance of plus maze. In this group, upregulation of peripheral benzodiazepine receptor of olfactory bulb was not observed. Ro5-4864, a peripheral benzodiazepine receptor agonist, elicited an increase of anxiolytic response on the performance of plus maze. Progesterone, a precursor of neuroactive steroid, also increased anxiolytic response on the performance of plus maze. Pretreatment with PK11195, a peripheral benzodiazepine receptor antagonist, abolshed the anxiolytic effect of progesterone. CONCLUSIONS: From these results, it could be concluded that peripheral benzodiazepine receptor is closely associated with the relief of acute stress induced anxiety response via an increase of synthesis of neuroactive steroid.