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目的：观察氧自由基对心肌细胞核钙转运系统的影响。方法：大鼠心肌细胞核采用蔗糖密度梯度离心分离纯化，用酶学方法测定ＡＴＰａｓｅ活性，用４５Ｃａ２＋同位素法测定核钙摄取。结果：低浓度的Ｈ２Ｏ２（１０μｍｏｌ／Ｌ）短时间作用使核钙泵活性增加３１．６％（Ｐ＜０．０５），高浓度Ｈ２Ｏ２（＞２０ｍｏｌ／Ｌ）使核钙泵活性降低（Ｐ＜０．０５），呈时间和剂量依赖性。低浓度ＯＨ短时间作用后，核钙泵活性显著增加４５．８％（Ｐ＜０．０１），但高浓度长时间作用后核钙泵活性显著降低（Ｐ＜０．０１）。２００μｍｏｌ／Ｌ的Ｈ２Ｏ２作用于心肌细胞核３０ｍｉｎ，核４５Ｃａ２＋摄取增加７０．４％（Ｐ＜０．０５），至６０ｍｉｎ恢复对照水平；ＯＨ显著刺激心肌细胞核４５Ｃａ２＋摄取，１０～６０ｍｉｎ末核４５Ｃａ２＋摄取增加１１．１～１６．８倍（Ｐ＜０．０１）。结论：上述结果表明，氧自由基影响心肌核钙转运系统的钙转运
Objective: To observe the effects of oxygen free radicals on the nuclear calcium transport system in cardiac myocytes. Methods: The myocardial nuclei of rats were isolated and purified by sucrose density gradient centrifugation. The ATPase activity was determined by enzymatic method and the nuclear calcium uptake was measured by 45Ca2 + isotope method. Results: The activity of nuclear calcium pump increased by 31.6% (P <0.05) in a short time with low concentration of H2O2 (10μmol / L), but decreased with high concentration of H2O2 (> 20mol / L) (P < 0.05), in a time and dose-dependent manner. The activity of nuclear calcium pump increased significantly by 45.8% (P <0.01) after low concentrations of OH for a short time, but decreased significantly after a long time of high concentration (P <0.01). 200μmol / L H2O2 for 30min, the nuclear 45Ca2 + uptake increased by 70.4% (P <0.05), and returned to the control level at 60min; OH up-regulated the uptake of 45Ca2 + in myocardial cells and up-regulated the uptake of 45Ca2 + in 10-60min .1 ~ 16.8 times (P <0.01). Conclusion: The above results show that oxygen free radicals affect calcium transport in the cardiac nuclear calcium transport system