| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2001: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1998: ¥900,000 (Direct Cost: ¥900,000)
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| Research Abstract |
Previous studies, by others and by us, have shown that neuronal stress and injury in the epileptic brain significantly alter polyamine metabolism, resulting in a marked elevation of the putrescine level. Recently, it was also reported that brain polyamine metabolism is modified by traumatic stress and may be involved in affective disorders. In this study, we measured the polyamine levels in the frontal cortex, hippocampus, hypothalamus, and plasma after applying water-immersion restraint stress, to further clarify the relationship between polyamines and traumatic stress. To stress mice, they were confined in a restraint stress-cage and immersed in water maintained at 25℃ for 2h. The animals were decapitated 5min, 6h, 24h and 48h after the cessation of stress. In all parts of the brain, the putrescine levels were significantly elevated 24h after stress application. The spermidine and spermine levels were unchanged or slightly reduced in the frontal cortex and hypothalamus 6h and 24h after stress application. In the plasma, there is no change in polyamine levels at any time intervals after stress application. In the case of restraint stress without water-immersion, putrescine level was increased only in the frontal cortex. Pretreatment with diazepam (5mg/kg, i. p.) reduced the stress-induced polyamine changes. These results indicate that the change of polyamine metabolism is linked to traumatic stress and its magnitude appears to be related to the intensity of the stressor.
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