Nonoda K, Matsubara T, Kanashiro M, Suzuki O, Nakao M, Sakamoto N
Third Department of Internal Medicine, Nagoya University School of Medicine, Japan.
Jpn Heart J. 1993 Sep;34(5):591-9. doi: 10.1536/ihj.34.591.
This study examined the effects of ischemia/reperfusion on cardiac function and diabetes-associated lipid peroxidation and scavenger induction in isolated working hearts. Cardiac function in diabetic rats was depressed in proportion to the duration of diabetes. Plasma levels of malondialdehyde (MDA) were increased significantly after diabetes of 1-week duration (1wD). MDA levels in the myocardium were increased significantly after 4-weeks (4wD) and tissue superoxide dismutase (SOD) activity was also elevated significantly in 8-week diabetic rats (8wD) as compared to control values. In both controls and diabetics, tissue MDA concentrations increased significantly during the first 3 min of reperfusion following 20 min of ischemia, compared with preischemia levels. At the end of reperfusion, tissue MDA levels decreased in controls and 1wD hearts, but remained elevated in the 4wD and 8wD cases. The SOD activity in 8wD hearts decreased significantly after 20 min of global ischemia followed by 30 min reperfusion, compared with preischemia levels. By contrast, there were no significant differences between preischemic and after-reperfusion data for parameters of cardiac function in 8wD rats. Thus, lipid peroxidation appears to have little influence on cardiac function during ischemia/reperfusion in rats with chronic diabetes.
本研究检测了缺血/再灌注对离体工作心脏的心功能、糖尿病相关脂质过氧化及清除剂诱导的影响。糖尿病大鼠的心功能随着糖尿病病程的延长而降低。糖尿病病程1周（1wD）后，血浆丙二醛（MDA）水平显著升高。与对照值相比，糖尿病病程4周（4wD）后心肌MDA水平显著升高，糖尿病病程8周（8wD）大鼠的组织超氧化物歧化酶（SOD）活性也显著升高。与缺血前水平相比，在对照组和糖尿病组中，缺血20分钟后再灌注的最初3分钟内，组织MDA浓度均显著升高。再灌注结束时，对照组和1wD心脏的组织MDA水平下降，但在4wD和8wD组中仍保持升高。与缺血前水平相比，8wD心脏在全心缺血20分钟后再灌注30分钟，其SOD活性显著降低。相比之下，8wD大鼠缺血前和再灌注后心功能参数的数据无显著差异。因此，在慢性糖尿病大鼠的缺血/再灌注过程中，脂质过氧化似乎对心功能影响不大。
