McMurray J, Chopra M, Abdullah I, Smith W E, Dargie H J
Department of Cardiology, Western Infirmary, Glasgow.
Br Heart J. 1992 Nov;68(5):454-7. doi: 10.1136/hrt.68.11.454.
To determine whether unstable angina, which is characterised by recurring episodes of myocardial ischaemia and reperfusion, is associated with oxidative stress (that is, where there is an imbalance between oxidants, such as free radicals, which are in excess and antioxidants).
Between group comparison of patients with unstable angina, stable angina, and healthy controls.
The coronary care unit and cardiac investigation ward of a regional cardiology centre.
Twenty five consecutive patients admitted to the coronary care unit with unstable angina. Twenty five consecutive patients admitted to the cardiac investigation ward (patients with stable angina undergoing coronary angiography) were used as controls for the presence of atherosclerosis, drug treatment, and smoking habit. Thirty eight healthy controls (hospital staff and patients admitted for minor surgical procedures who were otherwise healthy) were also studied.
Thiobarbituric acid related substances (TBARS) in plasma and plasma reduced thiol (PSH) as indicators of oxidative damage to lipids and proteins respectively were measured. Coronary angiography was performed in all patients with stable angina and roughly half of those with unstable angina.
Mean (SEM) plasma TBARS in unstable angina and stable angina were 9.95 (0.36) nmol/ml and 9.14 (0.28) nmol/ml respectively (p = 0.08). Mean plasma TBARS in healthy controls were 8.09 (0.21) nmol/ml (p < 0.05 compared with both angina groups). Mean (SEM) PSH concentration in unstable angina was 4.21 (9) nmol/ml and in stable angina was 4.85 (9) nmol/ml (p < 0.05). Mean PSH in healthy controls was 5.64 (8) nmol/ml (p < 0.001 compared with both angina groups). The extent of coronary artery disease, use of medication, and smoking habit were not significantly different between the angina groups.
Biochemical indicators of oxidative stress are more abnormal in unstable than stable angina. This is in keeping with experimental evidence that episodes of ischaemia and reperfusion lead to generation of free radicals and toxic oxygen species and depression of endogenous antioxidant activity. The clinical significance of this finding remains to be determined, although, experimentally, free radicals and toxic oxygen species have adverse effects on myocardial contractile function, myocardial electrical stability, endothelial mediated vasodilatation, and coagulation.
确定以反复出现心肌缺血和再灌注为特征的不稳定型心绞痛是否与氧化应激相关（即自由基等氧化剂过量与抗氧化剂之间存在失衡的情况）。
对不稳定型心绞痛患者、稳定型心绞痛患者和健康对照者进行组间比较。
某地区心脏病中心的冠心病监护病房和心脏检查病房。
25例连续入住冠心病监护病房的不稳定型心绞痛患者。25例连续入住心脏检查病房（正在接受冠状动脉造影的稳定型心绞痛患者）作为动脉粥样硬化、药物治疗和吸烟习惯方面的对照。还研究了38名健康对照者（医院工作人员和因小手术入院且其他方面健康的患者）。
分别测量血浆中硫代巴比妥酸相关物质（TBARS）和血浆还原型巯基（PSH），作为脂质和蛋白质氧化损伤的指标。对所有稳定型心绞痛患者以及约一半不稳定型心绞痛患者进行冠状动脉造影。
不稳定型心绞痛组和稳定型心绞痛组的平均（标准误）血浆TBARS分别为9.95（0.36）nmol/ml和9.14（0.28）nmol/ml（p = 0.08）。健康对照者的平均血浆TBARS为8.09（0.21）nmol/ml（与两组心绞痛患者相比，p < 0.05）。不稳定型心绞痛组的平均（标准误）PSH浓度为4.21（9）nmol/ml，稳定型心绞痛组为4.85（9）nmol/ml（p < 0.05）。健康对照者的平均PSH为5.64（8）nmol/ml（与两组心绞痛患者相比，p < 0.001）。心绞痛组之间冠状动脉疾病的程度、药物使用情况和吸烟习惯无显著差异。
不稳定型心绞痛中氧化应激的生化指标比稳定型心绞痛更异常。这与实验证据相符，即缺血和再灌注发作会导致自由基和毒性氧物质的产生以及内源性抗氧化活性的降低。尽管在实验中自由基和毒性氧物质对心肌收缩功能、心肌电稳定性、内皮介导的血管舒张和凝血有不良影响，但这一发现的临床意义仍有待确定。
