Psychiatric Centre Copenhagen, Copenhagen, Denmark.
PLoS One. 2011;6(6):e20795. doi: 10.1371/journal.pone.0020795. Epub 2011 Jun 7.
Chronic psychological stress is associated with accelerated aging, but the underlying biological mechanisms are not known. Prolonged elevations of the stress hormone cortisol is suspected to play a critical role. Through its actions, cortisol may potentially induce oxidatively generated damage to cellular constituents such as DNA and RNA, a phenomenon which has been implicated in aging processes. We investigated the relationship between 24 h excretion of urinary cortisol and markers of oxidatively generated DNA and RNA damage, 8-oxo-7,8-dihydro-2'-deoxyguanosine and 8-oxo-7,8-dihydroguanosine, in a sample of 220 elderly men and women (age 65-83 years). We found a robust association between the excretion of cortisol and the oxidation markers (R(2) = 0.15, P<0.001 for both markers). Individuals in the highest quartile of cortisol excretion had a 57% and 61% higher median excretion of the DNA and RNA oxidation marker, respectively, than individuals in the lowest quartile. The finding adds support to the hypothesis that cortisol-induced damage to DNA/RNA is an explanatory factor in the complex relation between stress, aging and disease.
慢性心理压力与加速衰老有关，但其中的生物学机制尚不清楚。人们怀疑长期升高的应激激素皮质醇起着关键作用。通过其作用，皮质醇可能潜在地诱导细胞成分（如 DNA 和 RNA）的氧化性损伤，这种现象与衰老过程有关。我们研究了 220 名老年男性和女性（年龄 65-83 岁）中 24 小时尿皮质醇排泄与氧化生成的 DNA 和 RNA 损伤标志物 8-氧代-7,8-二氢-2'-脱氧鸟苷和 8-氧代-7,8-二氢鸟苷之间的关系。我们发现皮质醇的排泄与氧化标志物之间存在很强的相关性（两个标志物的 R(2)分别为 0.15 和 P<0.001）。皮质醇排泄量最高四分位的个体的 DNA 和 RNA 氧化标志物的中位数排泄量比最低四分位的个体分别高出 57%和 61%。这一发现为皮质醇诱导的 DNA/RNA 损伤是应激、衰老和疾病之间复杂关系的一个解释因素的假设提供了支持。
