Objectives : There is a hypothesis that subject may adapted to same kind repetitive stress. Polyamine(putrescine, spermidine, and spermine) is one of the stress responses in brain and peripheral organs. Therefore, we designed this study to investigate the differences between single and complex type of chronic stresses by examining the changes of polyamine levels in brain and peripheral tissues.
Method :There are four groups in this study. 1) control group(n=5) :animals vdith no stress, 2) immobilization stress group(n=5) :animals with 10 times of immobilization stress, 3) cold-water swimming stress group(n=5) animals with 10 times of swimming stress in cold water, 4) complex stress group(n==5) :animals with immobilization and cold-water swimming stress. For immobilization stress(10 days), rats were placed in restrainers once daily, for :S hours. For cold water swimming stress, rats were placed in ice-cold water once daily for 3min(10 days). For complex stress, rats were alternately underwent immobilization stress and cold :swim stress, for 10 ~~ays(5 times, respectively). For polyamine analysis, polyamine extracted from brain tissue(frontal cortex and hippoc;ampus) and gasl:rointestinal tract(gastric and duodenal mucosa) and measured with high performance liquid chromatography and ultraviolet detector at 242nm.
Results : Putrescine levels in frontal cortex were significantly decreased by immobilization stress and complex stress, respectively. Putrescine levels in hippocampus were significantly decreased by immobilization stress. Spe~rmidine levels in duodenal mucosa were significantly decreased by cold swimming stress. However, spermine levels were not changed by any type of stress. There were no differences in polyamine reponses bE:tween single type and complex type stresses.
Conclusions :Attenuations of putrescine and spermidine levels .after chronic stresses seem to be a adaptation process of polyamine responses. In our experimental conditions, -there are no differences in polyamine responses between single type and complex type stresses.
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