Studies On The Effects Of Estrogen Of NF-κB And Calcium During Hypoxia And Reoxygenation In Cardiac Myocytes

Estrogen has evidently protective effects on cardiomyocytes during the progress of hypoxia and reoxygenation,but its exactly mechanisms is not clear.Calcium overload and NF-κB activation are important factors which cause injury during the progress of hypoxia and reoxygenation.Whether NF-κB activation is relates to calcium overload during the progress of hypoxia and reoxygenation is unknown.we observed the changes of NF-κB and calcium during various periods of time and investigated the interaction between NF-κB and calcium.Furthermore,this study was to initially investigate the effects of pretreatment with estrogen on NF-κB and cacium.The models of myocardial hypoxia/reoxygenation injury were made,wether it was successflly established with the standardization of biochemical indicator (LDH,CK,MDA) and survival rate of cells which we used FCM and MTT to test.The calcium concentration was detected by immunofluorescence and quantitation of activated NF-κB p65 was detected by WESTERN BLOT,we observed the changes of NF-κB p65,calcium overload and the effect of estrogen during the progress of hypoxia and reoxygenation.We detected the calcium concentration and NF-κB activation with FCM and immunohistochemistry in various reperfusion periods of time to determine the relation of calcium concentration and NF-κB activation.We pretreated with pyrrolidine dithiocarbamate known as a specific inhibitor of NF-κB, nimodipine known as a specific inhibitor of calcium overload,and both of them to observe changes of the same indexs with Laser confocal microscope.We obviously get something from results as following:The cell survival rate decreased in H/R,but estrogen can prevent it.Both calcium concentration and quantitation of activated NF-κB p65 increased in H/R,but estrogen also can prevent it.Calcium concentration and quantitation of activated NF-κB p65 are linear correlation in various periods of time reperfusion.Nimodipine can prevent calcium overload and inhibit NF-κB p65 activation.pyrrolidine dithiocarbamate inhibit NF-κBp65 activation,but it can not prenvent calcium overload. We can get conclusions as following: the protective effects of estrogen is related with the inhibition of NF-κB activation and calcium overload during hypoxia and reoxygenation in cardiac myocytes,meanwhile NF-κB p65 activation is related with calcium overload.