Department of Experimental and Applied Genetics, Slovak Medical University, Limbova 12, 833 03 Bratislava, Slovakia.
Eur J Nutr. 2011 Sep;50(6):437-46. doi: 10.1007/s00394-010-0147-2. Epub 2010 Dec 9.
Glutathione S-transferases (GSTs) are intimately involved in combating oxidative stress and in detoxifying xenobiotics. Our objective was to examine possible interactions between polymorphisms in GST genes and plasma vitamin C, tocopherols and carotenoids in 149 reference subjects and 239 subjects occupationally exposed to mineral fibres (asbestos, rock wool, glass fibre), agents that induce oxidative stress.
Deletion of GSTM1 and GSTT1, and substitution 105Ile/Val in GSTP1 genes were determined by PCR, antioxidants in plasma were measured by HPLC.
Tocopherols and carotenoids were affected by age, sex, smoking, occupational exposure to fibres, but not by GST polymorphisms. Vitamin C level was influenced by sex, smoking and occupational exposure. Subjects with deletion of GST had lower vitamin C levels compared with subjects carrying the functional gene variant. Vitamin C levels varied according to GSTM1 polymorphism in the whole group (p < 0.05), in all reference subjects (p < 0.05), in the asbestos factory reference group (p < 0.05), and according to GSTT1 polymorphism in reference group of the rock wool plant (p < 0.05). Vitamin C levels were approximately 20% lower in subjects with both functionally deficient genes in the whole group (p < 0.01) and in all non-exposed subjects (p < 0.05).
The correspondence of lower vitamin C levels with non-functional GST isoenzymes may indicate a causal connection between two antioxidant defence pathways, also the underlying mechanism is not yet clear. It seems that supplementation by natural antioxidants is particularly important for subjects with unfavourable genetic makeup and in those exposed to oxidative stress.
谷胱甘肽 S-转移酶（GSTs）在对抗氧化应激和解毒外来物质方面起着重要作用。我们的目的是在 149 名参考对象和 239 名职业暴露于矿物纤维（石棉、岩棉、玻璃纤维）的对象中，研究 GST 基因多态性与血浆维生素 C、生育酚和类胡萝卜素之间可能存在的相互作用，这些对象是诱导氧化应激的物质。
通过 PCR 法检测 GSTM1 和 GSTT1 的缺失以及 GSTP1 基因 105Ile/Val 的取代，用 HPLC 法测量血浆中的抗氧化剂。
生育酚和类胡萝卜素受年龄、性别、吸烟、职业纤维暴露的影响，但不受 GST 多态性的影响。维生素 C 水平受性别、吸烟和职业暴露的影响。与携带功能基因变异体的个体相比，缺失 GST 的个体维生素 C 水平较低。维生素 C 水平在整个组（p < 0.05）、所有参考对象（p < 0.05）、石棉厂参考组（p < 0.05）中根据 GSTM1 多态性变化，在岩棉厂参考组中根据 GSTT1 多态性变化（p < 0.05）。在整个组（p < 0.01）和所有非暴露组（p < 0.05）中，具有两种功能缺失基因的个体维生素 C 水平降低约 20%。
低水平的维生素 C 与非功能性 GST 同工酶相对应，可能表明两种抗氧化防御途径之间存在因果关系，其潜在机制尚不清楚。对于遗传背景不利的个体和暴露于氧化应激的个体，补充天然抗氧化剂可能尤为重要。
