Staats D A, Lohr D, Colby H D
Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford 61107.
Biochim Biophys Acta. 1988 Aug 12;961(3):279-84. doi: 10.1016/0005-2760(88)90074-4.
Lipid peroxidation in mitochondria from the functionally distinct inner (zona reticularis) and outer (zona fasciculata + zona glomerulosa) zones of the guinea-pig adrenal cortex was investigated. Ferrous ion (Fe2+)-induced lipid peroxidation was far greater in inner than outer zone mitochondria. Ascorbic acid similarly initiated lipid peroxidation to a greater extent in inner zone mitochondrial preparations. Differences in the unsaturated fatty acid content of inner and outer zone mitochondria could not account for the regional differences in lipid peroxidation. Total fatty acid concentrations were greater in the outer than in the inner zone, and the relative amounts of each fatty acid were similar in the two zones. However, mitochondrial concentrations of alpha-tocopherol, an antioxidant known to inhibit lipid peroxidation, were approx. 5-times greater in the outer than inner zone. The results demonstrate that there are regional differences in mitochondrial lipid peroxidation in the adrenal cortex which may be attributable to differences in alpha-tocopherol content. Thus, alpha-tocopherol may serve to protect outer zone mitochondrial enzymes from the consequences of lipid peroxidation and thereby contribute to some of the functional differences between the zones of the adrenal cortex.
对豚鼠肾上腺皮质功能不同的内层（网状带）和外层（束状带+球状带）线粒体中的脂质过氧化作用进行了研究。亚铁离子（Fe2+）诱导的脂质过氧化作用在内层线粒体中比外层线粒体中要强得多。抗坏血酸同样在内层线粒体制剂中引发脂质过氧化的程度更大。内层和外层线粒体不饱和脂肪酸含量的差异并不能解释脂质过氧化的区域差异。外层总脂肪酸浓度高于内层，且两个区域中各脂肪酸的相对含量相似。然而，抗氧化剂α-生育酚（已知可抑制脂质过氧化）的线粒体浓度在外层比内层大约高5倍。结果表明，肾上腺皮质线粒体脂质过氧化存在区域差异，这可能归因于α-生育酚含量的差异。因此，α-生育酚可能有助于保护外层线粒体酶免受脂质过氧化后果的影响，从而导致肾上腺皮质各层之间的一些功能差异。
