Diazoxide preconditioning plus subsequent hypothermia increased resistance of rat cultured hippocampal neurons against hypoxia-reoxygenation injury  

作　　者：LIU Rong-guo WANG Wei-jian S0NG Na CHEN Yan-qing LI Li-huan 

机构地区：[1]Department of Anesthesiology, Fujian Provincial Hospital, Fuzhou 350001, China [2]Department of Anesthesiology, First Affiliated Hospital of Wenzhou Medical College, Wenzhou 325000,China [3]Department of Anesthesiology, Cardiovascular Institute, Fuwai Hospital, Peking Union Medical college and Chinese Academy of Medical Sciences, Beijing 100037, China

出　　处：《Chinese Medical Journal》2006年第11期887-893,共7页中华医学杂志（英文版）

基　　金：This study was supported by a grant from Specialized Research Fund for Doctoral Program of Higher Education, Ministry of Education of China (No. 20030023028).

摘　　要：Background Cerebral ischemia-reperfusion/hypoxia-reoxygenation insult triggers lots of pathophysiological and biochemical events that separately affect the evolution of cerebral damage. Accordingly, all known effective neuroprotective measures should be taken to get the optimal efficacy of therapy. This study was undertaken to investigate whether diazoxide （DZ） preconditioning combined with the following hypothermia could contribute to synergistic neuroprotection compared with either hypothermia or DZ preconditioning alone. Methods Cultured for 9-10 days in vitro, the hippocampal neurons of SD rats were preconditioned with DZ 0 pmol/L or DZ 250 pmol/L for 1 hour per day and this treatment lasted for 3 days. Subsequently, neurons were subjected to deprivation of oxygen for 4 hours at 37°0, 34°C, 30℃ and 22℃, respectively. This experiment consisted of 8 groups （4 temperature groups and 4 combination groups） and each group contained 12-well or 2-dish cells. Survival rate, expression of Bcl-2, fluorescence magnitude of intracellular calcium, and concentration of malondialdehyde （MDA） were determined at 24 hours after reoxygenation. Results The survival rate and expression of Bcl-2 were both increased in individually hypothermic conditions compared with those at 370G （P〈0.05）, whereas intracellular calcium and MDA did the opposite exhibition simultaneously （P〈0.05）. 22℃ contributed to a higher survival rate and greater expression of Bcl-2 in comparison with other hypothermia （P〈0.05）. Preceding administration of 250 pmol/L DZ took the similar effects on the neurons like hypothermia. Moreover, compared with individual hypothermia or DZ preconditioning, the neuronal survival rate and expression of Bcl-2 in the combination group were increased significantly （P〈0.05）, whereas the calcium fluorescence density and concentration of MDA were reduced further （P〈0.05）. 250 Iamol/L DZ preconditioning combined with 22℃ provided a maximal neuroprotection. Conclusions Compared witBackground Cerebral ischemia-reperfusion/hypoxia-reoxygenation insult triggers lots of pathophysiological and biochemical events that separately affect the evolution of cerebral damage. Accordingly, all known effective neuroprotective measures should be taken to get the optimal efficacy of therapy. This study was undertaken to investigate whether diazoxide （DZ） preconditioning combined with the following hypothermia could contribute to synergistic neuroprotection compared with either hypothermia or DZ preconditioning alone. Methods Cultured for 9-10 days in vitro, the hippocampal neurons of SD rats were preconditioned with DZ 0 pmol/L or DZ 250 pmol/L for 1 hour per day and this treatment lasted for 3 days. Subsequently, neurons were subjected to deprivation of oxygen for 4 hours at 37°0, 34°C, 30℃ and 22℃, respectively. This experiment consisted of 8 groups （4 temperature groups and 4 combination groups） and each group contained 12-well or 2-dish cells. Survival rate, expression of Bcl-2, fluorescence magnitude of intracellular calcium, and concentration of malondialdehyde （MDA） were determined at 24 hours after reoxygenation. Results The survival rate and expression of Bcl-2 were both increased in individually hypothermic conditions compared with those at 370G （P〈0.05）, whereas intracellular calcium and MDA did the opposite exhibition simultaneously （P〈0.05）. 22℃ contributed to a higher survival rate and greater expression of Bcl-2 in comparison with other hypothermia （P〈0.05）. Preceding administration of 250 pmol/L DZ took the similar effects on the neurons like hypothermia. Moreover, compared with individual hypothermia or DZ preconditioning, the neuronal survival rate and expression of Bcl-2 in the combination group were increased significantly （P〈0.05）, whereas the calcium fluorescence density and concentration of MDA were reduced further （P〈0.05）. 250 Iamol/L DZ preconditioning combined with 22℃ provided a maximal neuroprotection. Conclusions Compared wit

关 键 词：DIAZOXIDE HYPOTHERMIA proto-oncogene protein c-bcl-2 CALCIUM MALONDIALDEHYDE 

分 类 号：R74[医药卫生—神经病学与精神病学]