RESUMEN
<p><b>AIM</b>To investigate the changes in the expression of four kinds of calcium regulatory proteins mRNA on the isolated ischemia/ reperfusion (IR) hearts.</p><p><b>METHODS</b>The rat hearts were divided into two groups: control group and IR group which received 45 min exposure to Krebs-Henseleit solution after 15 min zero-flow global ischemia. The indexes of left ventricular function, such as LVDP, +dp/dt(max), -dp/dt(max), and an arrhythmia scoring system were compared between the two groups. The messenger ribonucleic acid (mRNA) amount of sarcoplasmic reticulum (SR) Ca2+ ATPase (SERCA), phospholamban (PLB), inositol 1,4,5-trisphosphate receptor2 (IP3R2) and ryanodine receptor2 (RyR2) was measured by reverse transcription-polymerase chain reaction (RT-PCR) and normalized to the mRNA levels of beta-actin.</p><p><b>RESULTS</b>In the IR group, LVDP, +dp/dt(max) and -dp/dt(min) of the isolated hearts were depressed and the high rate of arrhythmias occurred during reperfusion. The levels of SERCA, IP3R2, RyR2 mRNA were lower in the IR isolated hearts group than those in the control group, while there was no difference in the level of phospholamban.</p><p><b>CONCLUSION</b>These data suggest that myocardial ischemia/reperfusion can induce the depression of cardiac performance and an increased risk of arrhythmias, concomitant with the decrease in SERCA, IP3R2, RyR2 mRNA steady state levels.</p>