Kohman L J, Veit L J
Department of Surgery, SUNY Health Science Center, Syracuse 13210.
J Surg Res. 1991 Aug;51(2):133-7. doi: 10.1016/0022-4804(91)90083-x.
The response of neonatal myocardium to ischemia and reperfusion was observed in an isolated working heart model using neonatal rabbits and compared to that of the adult rabbit heart. Lipid peroxidation occurring during ischemia and that occurring during reperfusion were evaluated separately. Malondialdehyde (MDA) in heart tissue was measured as an index of lipid peroxidation, and the occurrence of oxygen free radical damage was assessed by the effects of the scavengers, superoxide dismutase and catalase, on MDA production. Baseline MDA levels were similar in neonatal and adult hearts, were changed little by treatment with normoxic cardioplegia, and were elevated in both groups by treatment with hyperoxic cardioplegia. Thus, the degree of lipid peroxidation during ischemia is similar in neonatal and adult hearts. After 10 min of retrograde reperfusion subsequent to treatment with anoxic cardioplegia, the MDA content of adult hearts was significantly greater than that of similarly treated neonatal hearts. Addition of free radical scavengers to the reperfusion medium lowered the MDA content of adult hearts significantly, but not to the level of neonatal hearts. After 60 min of reperfusion subsequent to hyperoxic cardioplegia, adult hearts had higher MDA than neonates; addition of scavengers to the cardioplegia did not lower the MDA significantly in either group. Only 5 of 12 adult hearts recovered function after hyperoxic cardioplegia, while all 12 neonatal hearts recovered. Our results indicate that neonatal myocardium suffers less damage from oxygen-centered free radicals during reperfusion than does adult myocardium.
在使用新生兔的离体工作心脏模型中观察了新生心肌对缺血和再灌注的反应，并与成年兔心脏进行了比较。分别评估了缺血期间和再灌注期间发生的脂质过氧化。测量心脏组织中的丙二醛（MDA）作为脂质过氧化的指标，并通过清除剂超氧化物歧化酶和过氧化氢酶对MDA产生的影响来评估氧自由基损伤的发生情况。新生心脏和成年心脏的基线MDA水平相似，用常氧心脏停搏液处理后变化不大，而用高氧心脏停搏液处理后两组均升高。因此，新生心脏和成年心脏在缺血期间的脂质过氧化程度相似。在用缺氧心脏停搏液处理后进行10分钟逆行再灌注后，成年心脏的MDA含量明显高于同样处理的新生心脏。向再灌注培养基中添加自由基清除剂可显著降低成年心脏的MDA含量，但未降至新生心脏的水平。在用高氧心脏停搏液处理后进行60分钟再灌注后，成年心脏的MDA含量高于新生心脏；向心脏停搏液中添加清除剂并未显著降低两组的MDA含量。在高氧心脏停搏液处理后，12只成年心脏中只有5只恢复了功能，而所有12只新生心脏均恢复了功能。我们的结果表明，与成年心肌相比，新生心肌在再灌注期间受到以氧为中心的自由基的损伤较小。
