Korean J Psychopharmacol.
2000 Jun;11(2):160-167.
Effect of Melatonin Administration on the Immobilization Stress-induced
Polyamine Responses in Brain and Gastrointestinal Tract
- Affiliations
-
- 1Department of Internal Medicine, School of Medicine, Keimyung University, Taegu, Korea.
- 2Department of Pharmacology, School of Medicine, Keimyung University, Taegu, Korea.
Abstract
OBJECTIVE
The present study was designed to identify the acute and chronic immobilization
stress-induced polyamine (putrescine) responses and their modulation by administration of
melatonin in brain regions (frontal cortex and hippocampus) and gastrointestinal tract
regions (GIT, gastric mucosa and duodenal mucosa).
METHOD: For immobilization stress (3 or 14 days), rats (250-300 g, male Sprague-Dawley rats)
were placed in restrainers once daily, for 3 h. Melatonin (10 mg/kg, i.p.) was administered
once daily immediately after stress. Rats were sacrificed 2 h after the final application
of stress for the measurement of putrescine levels.
RESULTS
The putrescine levels of frontal cortex, hippocampus, gastric mucosa and duodenal
mucosa were significantly increased by acute stress (p<0.05, p<0.05, p<0.0005 and p<0.01,
respectively). The putrescine levels of frontal cortex and duodenal mucosa were significantly
increased by chronic stress (p<0.05, respectively). In chronic stress group, animals showed
adaptation tendency. The changes of putrescine level in gastric and duodenal mucosa induced
by chronic stress were significantly lower than those by acute stress
(p<0.05, respectively). The putrescine responses to acute stress in frontal cortex,
hippocampus, gastric mucosa and duodenal mucosa were attenuated by administration of
melatonin (p<0.01, p<0.05, p<0.05 and p<0.05, respectively). The putrescine
response to chronic stress in frontal cortex was attenuated by melatonin administration
(p<0.05, respectively).
CONCLUSION
The results suggested that putrescine may play a role in stress response of
brain regions (frontal cortex and hippocampus) and GIT regions (gastric and duodenal mucosa).
Melatonin can inhibit the stress-induced putrescine responses in the brain and GIT.