三碘甲腺原氨酸对心肌细胞能量代谢的影响及其在心肌保护中的作用

目的 研究不同甲状腺功能状态下，三碘甲腺原氨酸（T3）对大鼠缺血再灌注（I/R）心肌细胞能量代谢的影响，探讨T3在心肌保护中的作用。方法 将实验大鼠分为甲状腺功能正常（A组）和甲状腺功能减退（甲减，B组）组，两组又随机分成空白缺血组、单纯灌注液组、T3灌注液组；建立离体心工作模型；利用反相高效液相色谱法测定各组心肌细胞ATP、ADP、AMP含量。结果 甲减状态心肌细胞ATP、ADP、AMP含量均明显降低（P<0.01）；I/R过程中，A、B两组ATP、ADP、AMP含量均大幅度下降，然而，T3灌注液组ATP含量显著高于单纯灌注液组：A组（1.03±0.02）vs（0.62±0.02）(mol/g，B组（0.85±0.02）vs（0.40±0.01）(mol/g，P<0.01。结论 甲减或I/R损伤使心肌细胞的能量合成及利用受到严重损害，T3可明显增加心肌细胞ATP的合成量与储备量，具有良好的心肌保护作用。

The effects of triiodothyronine on energy metabolism and myocardial protection

Objective To observe the effects of triiodothyronine (T3) on myocardial energy metabolism and its protection of the myocardial cells in rat ischemic reperfusion myocardial model with different thyroid functions. Methods The rats were categorized into group A (with normal thyroid function) and group B (with hypothyroidism), and each group were divided into blank control group, ischemic group, control reperfusion group and T3 reperfusion group. An isolated rat heart working model was established. The contents of ATP, ADP, AMP in the myocardial tissue in different groups were measured by high-performance liquid chromatographic method. Results The contents of ATP, ADP, AMP declined markedly in hypothyroidism group (P<0.01). Thirty minutes of ischemic arrest induced significant decrease of, ATP, ADP and AMP contents both groups A and B, which further declined when the hearts were subjected to 20 min of reperfusion. However ,the content of ATP increased markedly in T3 reperfusion groups compared with the control reperfusion groups in both group A:(1.03±0.02) vs (0.62±0.02) mmol/g and group B:(0.85±0.02) vs (0.40±0.01)] mmol/g (P<0.01). Conclusions Hypothyroidism or ischemic reperfusion injury may badly damage myocardial energy metabolism; T3 coold markedly increase the capacities of synthesizing and reserving ATP, improving myocardial protection.