Lapenna D, Mezzetti A, de Gioia S, Consoli A, Festi D, Di Ilio C, Cuccurullo F
Cattedra di Patologia Speciale Medica, Università G. D'Annunzio, Presidenza Facoltà di Medicina e Chirurgia, Chieti, Italy.
Pflugers Arch. 1994 Jul;427(5-6):432-6. doi: 10.1007/BF00374257.
The left ventricular subendocardial and subepicardial layers of six perfused rabbit hearts were tested for enzymatic and non-enzymatic antioxidant defences and for lipid peroxidation. The subendocardium showed significantly lower catalase activity and contents of non-protein thiol compounds and vitamin E associated with a higher degree of lipid peroxidation. The activities of Cu,Zn- and Mn-superoxide dismutases, glutathione reductase, gamma-glutamylcysteine synthetase and gamma-glutamyl transpeptidase showed no significant transmural differences, and Se-independent glutathione peroxidase activity was not detectable in either layer. Comparable results were observed in another group of six unperfused rabbit hearts. In five H2O2-perfused rabbit hearts, lipid peroxidation was higher, and myocardial creatine phosphokinase activity lower, in the subendocardium than in the subepicardium. In this group, only the subendocardium had significantly higher lipid peroxidation levels than the control hearts. Thus, a lower antioxidant capacity and a greater oxidative stress are present in the rabbit subendocardium. These findings could provide insight into the problem of subendocardial vulnerability to free radical-mediated processes, such as occurs in ischaemia-reperfusion injury.
对六只灌注兔心脏的左心室心内膜下层和心外膜下层进行了酶促和非酶促抗氧化防御以及脂质过氧化检测。心内膜下层过氧化氢酶活性、非蛋白硫醇化合物含量和维生素E含量显著较低，同时脂质过氧化程度较高。铜锌超氧化物歧化酶、锰超氧化物歧化酶、谷胱甘肽还原酶、γ-谷氨酰半胱氨酸合成酶和γ-谷氨酰转肽酶的活性在跨壁上无显著差异，且两层中均未检测到不依赖硒的谷胱甘肽过氧化物酶活性。在另一组六只未灌注兔心脏中观察到了类似结果。在五只过氧化氢灌注的兔心脏中，心内膜下层的脂质过氧化程度高于心外膜下层，心肌肌酸磷酸激酶活性低于心外膜下层。在该组中，只有心内膜下层的脂质过氧化水平显著高于对照心脏。因此，兔心内膜下层存在较低的抗氧化能力和较大的氧化应激。这些发现可能有助于深入了解心内膜下层对自由基介导过程（如缺血再灌注损伤中发生的过程）的易损性问题。
