Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China.
J Biochem Mol Toxicol. 2010 Nov-Dec;24(6):361-7. doi: 10.1002/jbt.20347.
Microcystins (MCs) induce the production of reactive oxygen species (ROS) in various tissues in mammals, whereas the endogenous antioxidant enzymes are responsible to scavenge the ROS. ROS can modulate the antioxidant enzyme activities by regulating the mRNA levels. The present study was undertaken to find out the relationship between the transcriptional alterations of antioxidant enzymes and MCs stimulation in rats. The time-dependent changes of relative transcription abundance of catalase (CAT), Mn-superoxide dismutase (Mn-SOD), Cu,Zn-superoxide dismutase (Cu,Zn-SOD), glutathione reductase (GR), glutathione peroxidase (GPx), and gamma-glutamylcysteine synthetase (γ-GCS) were investigated in three organs (liver, kidney, and testis) of male Wistar rats injected intravenously (i.v.) with 80 μg MC-LR(equivalent)/kg body weight using the quantitative real-time PCR (qPCR) method. We found that MCs could affect the transcriptional activities of these antioxidant enzymes in liver, kidney, and testis of MCs-treated rats and we speculated the possible causation of the transcriptional change. The altered transcription of antioxidant enzymes may play an important role in counteracting the potential deleterious effects of elevated oxidative stress induced by MCs, and this will provide us new insights into the possible role of antioxidant enzymes in the toxicological mechanisms of MCs at molecular level.
微囊藻毒素 (MCs) 在哺乳动物的各种组织中诱导活性氧 (ROS) 的产生，而内源性抗氧化酶则负责清除 ROS。ROS 可以通过调节 mRNA 水平来调节抗氧化酶活性。本研究旨在探讨抗氧化酶的转录改变与 MCs 刺激大鼠之间的关系。采用实时定量 PCR (qPCR) 方法，研究了静脉注射 80μg MC-LR(相当于)/kg 体重 MC-LR 后雄性 Wistar 大鼠三个器官 (肝、肾和睾丸) 中过氧化氢酶 (CAT)、锰超氧化物歧化酶 (Mn-SOD)、铜锌超氧化物歧化酶 (Cu，Zn-SOD)、谷胱甘肽还原酶 (GR)、谷胱甘肽过氧化物酶 (GPx) 和γ-谷氨酰半胱氨酸合成酶 (γ-GCS) 的相对转录丰度的时间依赖性变化。结果发现，MCs 可影响 MCs 处理大鼠肝、肾和睾丸中这些抗氧化酶的转录活性，我们推测转录变化的可能原因。抗氧化酶的转录改变可能在对抗由 MCs 引起的氧化应激升高的潜在有害影响中发挥重要作用，这将为我们提供新的见解，了解抗氧化酶在 MCs 的毒理学机制中的可能作用在分子水平上。
