Mechanism of cal reticulin-mediated hypoxic preconditioning in protection of heart
Abstract：Objective To study the effect of hypoxic preconditioning (HPC) on myocardial calreti-culin (CRT ) expression and calcium homeostasis in sarcoplasmic reticulum (SR) and its signal transduction mechanism .Methods Twenty-two SD rats were randomly divided into sham opera-tion group(n=6) ,model group (n=8) ,and HPC group (n=8) .SD rat HPC model and myocardial infarction (MI) model were established .The LV ± dp/dtmax was assayed .The infarction size was measured by TTC .The SR vesicle was prepared and its purity was identified by differential cen-trifugation .The SR Ca2+ uptake and release were detected by Millipore filtration .CRT expression and p38MAPK phosphorylation were detected by Western blot .Results The LV + dp/dt max and -dp/dtmax were 39% and 46% lower in HPC group than in sham operation group (P<0 .05) , and 43% and 59% higher in HPC group than in model group (P<0 .05) .The SR Ca2+ uptake was higher and the SR Ca2+ release was lower in HPC group than in model group (P<0 .05) .The CRT expression and p38MAPK phosphorylation levels were higher in HPC group than in model group (P<0 .05) .Conclusion HPC can upregulate the Ca2+ expression ,improve the SR Ca2+ up-take and release ,and reduce the calcium overload in myocardiocytes through the p38MAPK path-way ,thus protecting the heart against ischemia injury .
Keywords：calreticulinanoxiap38 mitogen-activated protein kinasesmyocardial infarction
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 971-974 )