Zhan H, Dong H J, Xin Y M, Tang G X
Institute of Aviation Medicine, Beijing.
Space Med Med Eng (Beijing). 1999 Apr;12(2):79-83.
Objective. To observe the effects of tea polyphenols (TP) on cardiac function and myocardial ultrastructure in rats after repeated +10 Gz stress. Method. Twenty four male Wistar rats were randomly divided into three groups (n=8 each): group A (control), group B (+10 Gz), group C (+Gz with TP). Group B and C were repeatedly exposed to +10 Gz (each for 30 s, onset rate about 0.5 G/s, 3 times/d with +1 Gz 1 min intervals, 3 d/wk, 4 weeks in total), but group A was only submitted to +1 Gz. TP (200 mg kg-1) was given orally to group C about 1 h prior to the +Gz experiment, and distilled water was given to group A and B. Function of isolated rat working hearts and myocardial ultrastructure were observed. Result. A significant decrease of left ventricular systolic pressure (LVSP) and injury of myocardial structure in rats were demonstrated after repeated +10 Gz stress. But TP could remarkably elevate the LVSP and improve myocardial ultrastructural injury in +10 Gz stressed rats. Conclusion. These results indicated that repeated high G exposure may produce cardiac structural and functional injuries in rats which might be partly related to free radical metabolism; and antioxidant TP had significant protective effects on the hearts of +Gz stressed rats.
目的。观察茶多酚（TP）对反复 +10 Gz 应激后大鼠心脏功能及心肌超微结构的影响。方法。将 24 只雄性 Wistar 大鼠随机分为三组（每组 n = 8）：A 组（对照组）、B 组（+10 Gz 组）、C 组（+10 Gz 加 TP 组）。B 组和 C 组反复暴露于 +10 Gz（每次 30 秒，起始速率约 0.5 G/s，每天 3 次，每次间隔 1 分钟 +1 Gz，每周 3 天，共 4 周），但 A 组仅施加 +1 Gz。在 +10 Gz 实验前约 1 小时给 C 组口服 TP（200 mg/kg），给 A 组和 B 组给予蒸馏水。观察大鼠离体工作心脏功能及心肌超微结构。结果。反复 +10 Gz 应激后大鼠左心室收缩压（LVSP）显著降低且心肌结构受损。但 TP 可显著提高 +10 Gz 应激大鼠的 LVSP 并改善心肌超微结构损伤。结论。这些结果表明，反复高 G 暴露可能导致大鼠心脏结构和功能损伤，这可能部分与自由基代谢有关；抗氧化剂 TP 对 +10 Gz 应激大鼠心脏有显著保护作用。
