[Effects of calcium and calmodulin dependent kinase against hypoxic neuronal injury].
OBJECTIVE
To study the effects of calcium and calmodulin dependent kinase against hypoxic neuronal injury and its possible mechanisms.


METHODS
Embryonic cortical neurons of 17-day pregnant embryo Sprague-Dawley rats were cultured in vitro and the cultured neurons were randomly allocated into different groups that exposed to hypoxia or hypoxia +calcium channel antagonist. Nimodipine and MK-801 were used to block the L-voltage sensitive calcium channel and NMDA receptor respectively before hypoxia. The methyl thiazolyl tetrazolium (MTT) method was used to determine the cell viability. Fluo-4AM, an intracellular calcium indictor, was used to detect the changes of intracellular calcium after hypoxia. The expressions of CaMKII and CaMKIV were detected by Western blot.


RESULTS
The cell viability of the nimodipine or MK-801-treated groups was significantly higher than that of the untreated hypoxia group. The intracellular calcium level of the nimodipine-treated group decreased rapidly after hypoxia. Compared to nimodipine treatment, MK-801 treatment could inhibit hypoxia-induced calcium influx for a longer time. Nimodipine treatment decreased the CaMKII expression while MK-801 treatment decreased the CaMKIV expression.


CONCLUSIONS
Nimodipine and MK-801 protect neurons from hypoxic injury possibly by the inhibition of CaMKII and CaMKIV expressions respectively.
Zhou
Hui
H
Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China.
Sun
Xiao-Mei
XM
Luo
Xiao-Li
XL
Mao
Meng
M
D000818:Animals; D002118:Calcium / Q000032:analysis; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D015687:Cell Hypoxia; D016291:Dizocilpine Maleate / Q000494:pharmacology; D005260:Female; D009474:Neurons / Q000473:pathology*; D018696:Neuroprotective Agents / Q000494:pharmacology; D009553:Nimodipine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D018696:Neuroprotective Agents; D009553:Nimodipine; D016291:Dizocilpine Maleate; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517686:Camk4 protein, rat; D002118:Calcium