Traumatic stress causes post-traumatic stress disorder (PTSD). PTSD is associated with cardiovascular diseases and risk of sudden cardiac death in some subjects. We compared effects of predator stress (PS, cat urine scent, 10 days) on mechanisms of cardiac injury and protection in experimental PTSD-vulnerable (PTSD) and -resistant (PTSDr) rats. 14-days post-stress, rats were evaluated with an elevated plus-maze test, and assigned to PTSD and PTSDr groups according to an anxiety index calculated from the test results. Cardiac injury was evaluated by: 1) Exercise tolerance; 2) ECG; 3) Myocardial histomorphology; 4) Oxidative stress; 5) Pro- and anti-inflammatory cytokines. Myocardial heat shock protein 70 (HSP70) was also measured. Experimental PTSD developed in 40% of rats exposed to PS. Exercise tolerance of PTSD rats was 25% less than control rats and 21% less than PTSDr rats. ECG QRS, QT, and OTc intervals were longer in PTSD rats than in control and PTSDr rats. Only cardiomyocytes of PTSD rats had histomorphological signs of metabolic and hypoxic injury and impaired contractility. Oxidative stress markers were higher in PTSD than PTSDr rats. Pro-inflammatory IL-6 was higher in PTSD rats than in control and PTSDr rats, and anti-inflammatory IL-4 was lower in PTSD than in control and PTSDr rats. Myocardial HSP70 was lower in PTSD rats than PTSDr and control rats. Conclusion: Rats with PTSD developed multiple signs of cardiac injury. PTSDr rats were resistant also to cardiac injury. Factors that limit cardiac damage in PS rats include reduced inflammation and oxidative stress and increased protective HSP70.

中文翻译：

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实验性创伤后应激障碍 (ePTSD) 大鼠的心脏损伤及其对 ePTSD 抵抗大鼠的限制机制

创伤性应激会导致创伤后应激障碍（PTSD）。PTSD 与某些受试者的心血管疾病和心源性猝死风险相关。我们比较了捕食者应激（PS，猫尿气味，10 天）对实验性 PTSD 易感 (PTSD) 和抵抗 (PTSDr) 大鼠心脏损伤和保护机制的影响。应激后14天，用高架十字迷宫测试对大鼠进行评估，并根据测试结果计算的焦虑指数将其分配至PTSD组和PTSDr组。通过以下指标评估心脏损伤： 1) 运动耐量；2）心电图；3）心肌组织形态学；4）氧化应激；5) 促炎和抗炎细胞因子。还测量了心肌热休克蛋白 70 (HSP70)。40% 暴露于 PS 的大鼠出现实验性 PTSD。PTSD大鼠的运动耐量比对照大鼠低25%，比PTSDr大鼠低21%。PTSD 大鼠的心电图 QRS、QT 和 OTc 间期比对照组和 PTSDr 大鼠更长。只有 PTSD 大鼠的心肌细胞具有代谢和缺氧损伤以及收缩力受损的组织形态学迹象。PTSD 大鼠的氧化应激标志物高于 PTSDr 大鼠。PTSD 大鼠中的促炎性 IL-6 高于对照和 PTSDr 大鼠，而 PTSD 中的抗炎性 IL-4 低于对照和 PTSDr 大鼠。PTSD 大鼠的心肌 HSP70 低于 PTSDr 和对照大鼠。结论：患有 PTSD 的大鼠出现多种心脏损伤迹象。PTSDr 大鼠也能抵抗心脏损伤。限制 PS 大鼠心脏损伤的因素包括减少炎症和氧化应激以及增加保护性 HSP70。