中华哲水蚤抗氧化系统对海水酸化的响应

海洋浮游动物可以对因二氧化碳浓度升高导致的海水酸化做出敏感的响应，然而关于海水酸化对其生理机能的研究却较少。因此，我们研究了暴露于不同二氧化碳浓度（0.08,0.20,0.50 and 1.00%）的酸化条件下中华哲水蚤主要抗氧化酶以及2种解毒酶的活性变化情况。结果表明，暴露于酸化海水中的中华哲水蚤的GPx酶活性显著高于对照组，然而，其它抗氧化组分，包括GST、SOD活性，GSH水平和GSH/GSSG比值均被显著抑制。中华哲水蚤的ATPase活性被海水酸化显著刺激，而AchE活性却显著被抑制。此外，主成分分析结果表明，各指标变化的75.93%可以用第一和第二主成分解释。因二氧化碳浓度升高导致的海水酸化可以通过影响桡足类体内一些酶类的活性来影响其新陈代谢及存活。在未来的研究工作中，需要对海水酸化和其它环境因素的协同作用对桡足类的影响作进一步研究。

Response of antioxidant defense system in copepod Calanus sinicus Brodsky exposed to CO2-acidified seawater

Marine zooplankton responds sensitively to elevated seawater CO₂ concentration. However, the underlying physiological mechanisms have not been studied well. We therefore investigated the effects of elevated CO₂ concentration (0.08%, 0.20%, 0.50% and 1.00%) on antioxidant defense components, as well as two detoxification enzymes of Calanus sinicus (copepod). The results showed that glutathione peroxidase (GPx) activity exposed to CO₂-acidified seawater was significantly stimulated while other antioxidant components, including glutathione-Stransferase (GST) activity, superoxide dismutase (SOD) activity decreased significantly with reduced glutathione (GSH) level and GSH/oxidized glutathione (GSSG) value. CO₂-acidified seawater exhibited stimulatory effects on adenosine triphosphatase (ATPase) activity and acetylcholinesterase (AchE) activity was inhibited. Moreover, the results of principal component analysis indicated that 75.93% of the overall variance was explained by the first two principal components. The elevated CO₂ concentration may affect the metabolism and survivals of copepods through impacts these enzymes activities. Further studies are needed to focus on the synergistic effects of elevated CO₂ concentration and other environmental factors on copepods.