恶性肿瘤组织的氧化还原态及其抗氧化能力的改变

Alteration of the redox status and its antioxidative capability in the tissue of malignant tumors

目的探讨恶性肿瘤组织的氧化-还原态及其抗氧化能力的改变。方法42例原发性消化道恶性肿瘤(食管癌13例、胃癌14例及结直肠癌15例),以其相对应的癌旁正常粘膜组织为对照,测定其谷胱甘肽氧化还原对(GSH、GSSG)的含量及辅酶Ⅱ氧化还原对(NADPH、NADP+)的含量,并据此计算出GSH/GSSG、NADPH/NADP+比值以及GSH/GSSG氧化还原电位值、NADPH/NADP+氧化还原电位值。结果癌组织中的GSH、NADPH含量明显高于癌旁组织(P<0.01)。GSH/GSSG、NADPH/NADP+的氧化-还原电位轻度还原偏移(P<0.05)。而GSSG含量及NADP+含量则与对照组无明显差异(P>0.05)。结论消化道恶性肿瘤组织的GSH、NADPH含量明显升高,提示其抗氧化能力明显增强;而在此基础上,其氧化-还原电位仅较癌旁组织轻度偏向还原方向,提示癌组织内仍存有较明显的氧化应激态。

AIM： To investigate the changes of the redox status and the antioxidative capability in the tissue of malignant tumors. METHODS： The carcinoma tissues collected from 42 patients with primary cancer in digestive tract （ 13 eases of esophageal cancer, 14 cases of gastric cancer and 15 cases of colorectal cancer）, the corresponding paratumor mucosa tissues were taken as the control samples. The content of oxidized and reduced glutathion （GSSG and GSH）, oxidized and reduced coenzyme Ⅱ （NADP^＋ and NADPH） were measured, the GSH/GSSG, NADPH/NADP^＋ ratios, and the GSH/GSSG, NADPH./NADP^＋ redox potentials were calculated according to Nernst formula. RESULTS： The levels of GSH and NADPH in cancer tissues were significantly higher than those in corresponding paratumor tissues （ P 〈 0.01 ）. The GSH/GSSG redox potential and NADPH/NADP^＋ redox potential in cancer tissues, however, just slightly deviated to reductive state （a little more negative） than those in paratumor tissues （ P 〈 0.05）. The contents of GSSG and NADP^＋ had no apparent difference between cancer tissues and corresponding paratumor tissues （ P 〉 0.05）. CONCLUSIONS： The significant increase in GSH and NADPH contents in cancer tissues indicates a notable enhancement of its antioxidative capability compared with the corresponding paratumor tissues. Based on this changes, the redox potential in the cancer tissues has only slightly reductive shift, which may suggest an apparent oxidative stress existed in the caneer tissues.