Effects of calcium and calmodulin dependent kinase against hypoxic neuronal injury / 中国当代儿科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the effects of calcium and calmodulin dependent kinase against hypoxic neuronal injury and its possible mechanisms.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>Nimodipine and MK-801 protect neurons from hypoxic injury possibly by the inhibition of CaMKII and CaMKIV expressions respectively.</p>