[Dynamic changes of neurotrophic factors in different cerebral areas after full cerebral ischemia and reperfusion in old rats].

OBJECTIVE: To explore the relationship between vascular dementia and nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). METHODS: 42 male and female senile Wistar rats were randomized into control and experimental groups. The control group was subdivided into A, and C three groups and the experimental group into 6 subgroups, i.e 15 min of ischemia alone and ischemia combined with reperfusion of 1 h, 6 h, 2 d, 4 d and 9 d. Swimming maze was performed before and after operation. The contents of NGF and BDNF in different parts of brain were examined in different periods of ischemia and reperfusion with ABC method of immunocytochemistry. RESULTS: NGF expression in frontal lobes reached a peak level in 2 days after reperfusion and then disappeared quickly, that in parietal lobes showed a moderate level in 15 minutes of ischemia and reached a peak in 9 days of reperfusion. However, there is no expression in thalamus in early ischemia and reperfusion, but reexpression occurred after 2 days of reperfusion. BDNF expression showed a peak level after 2 days of reperfusion and then decreased in frontal lobes, but a high level of expression that was unchanged in parietal lobes and hippocampal areas. The increasing expression in thalamus occurred only 9 days after reperfusion. CONCLUSION: The distribution of BDNF was wider than that of NGF. There was a good protective action of NGF and BDNF in frontal lobes in the early period of ischemia with reperfusion and there existed persistent and prompt action of the neurotrophic factors in parietal lobes and hippocampal areas. The protective action of NGF in thalamus was poor, but that of BDNF was good.