Time window characteristics of cultured rat hippocampal neurons subjected to ischemia and reperfusion.
OBJECTIVE
To explore cell death and apoptosis in rat hippocampal neurons at different time points after ischemia, hypoxia and reperfusion injury and to elucidate time window characteristics in ischemia neuronal injury.


METHODS
Hippocampal neurons were obtained from rat embryo and were cultured in vitro. The ischemia and reperfusion of cultured rat hippocampal neurons were simulated by oxygen-glucose deprivation (OGD) and recovery. OGD at different time points (0.25 h to 3.0 h) and then the same recovery (24 h) were prepared. Annexin V-PI staining and flow cytometry examined neuron death and apoptosis at different time after injury.


RESULTS
After OGD and recovery, both necrosis and apoptosis were observed. At different times after OGD, there were statistically significant differences in neuron necrosis rate (P < 0.05), but not in apoptosis rate (P > 0.05). At recovery, survival rate of hippocampal neurons further decreased while apoptosis rate increased. Furthermore, apoptosis rates of different time differed greatly (P < 0.05). Apoptosis rate gradually increased with significant difference among those of different time points (P < 0.05). However, 2 h after ischemia, apoptosis rate decreased markedly.


CONCLUSIONS
Apoptosis is an important pathway of delayed neuron death. The therapeutic time window should be within 2 h after cerebral ischemia and hypoxia.
Xu
Zhong
Z
Department of Neurosurgery, Zhujiang Hospital, Nanfang Medical University, Guangdong 510282, China.
Xu
Ru-xiang
RX
Liu
Bao-song
BS
Jiang
Xiao-dan
XD
Huang
Tao
T
Ding
Lian-shu
LS
Yuan
Jun
J
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002545:Brain Ischemia / Q000473:pathology; D016923:Cell Death / Q000502:physiology; D015687:Cell Hypoxia; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D005333:Fetus / Q000166:cytology; D005434:Flow Cytometry; D006624:Hippocampus / Q000473:pathology*; D009474:Neurons / Q000473:pathology*; D011247:Pregnancy; D011270:Pregnancy, Animal; D011336:Probability; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000473:pathology; D012680:Sensitivity and Specificity; D013997:Time Factors