The Influences of Moderate Hypothermia on the Brain Neurotransmitter Content in the Gerbil Global Ischemic: Reperfusion Model

ABSTRACT

PURPOSE: Hypothermia induces tolerance to ischemic brain injury and has protective effects. The role of catecholamine and indole amine in ischemic brain injury has not been well documented. To investigate the relationships between hypothermia and catecholamines in ischemia-induced brain damage, we performed a quantitative measurements of the catecholamines in each brain region after a periods of ischemia and ischemia reperfusion. METHODS: By using the Gerbil global ischemic reperfusion model, we divided the experimental group into control, ischemia (10 minute), ischemia with hypothermia, ischemia reperfusion, and ischemia reperfusion with hypothermia groups. After periods of ischemia and ischemia reperfusion with or without hypothermia, the amine concentrations in five brain regions were measured using high performance liquid chromatography (HPLC). RESULTS: The norepinephrine (NE) content in the hippocampus was increased in the ischemia group and the ischemia reperfusion with hypothermia group, but diminished in the ischemia with hypothermia group and the ischemia reperfusion group (p<0.05). The dopamine content was decreased in the hippocampus in the ischemia with hypothermia group and was increased in the ischemia reperfusion with hypothermia group. However, the striatal dopamine content was increased in the ischemia with hypothermia. The contents of both 5-HT and 5-HIAA in the striatum of both referfusion groups were changed significantly. The contents of the other neurotansmitters were changed markedly, but the changes had no statistical significance. CONCLUSION: This study indicates that ischemia and hypothermia have great influences on amine contents of the brains, and suggests that much researches is required to elucidate the effects of hypothermia on the neurotransmitter content in ischemic-reperfusion brain injury.