Biological fouling is an unwanted phenomenon that results in economic losses to the shipping industry. To prevent fouling, antifouling paints are used. DCOIT (4,5- dichloro-2-n-octyl-4-isothiazolin-3-one) is a biocide present in many antifouling paint formulations, and is toxic to a wide range of organisms. The aim of the present study was to evaluate the effects of DCOIT on oxidative stress indicators of the brown mussel, Perna perna. Molecular (SOD-like, GSTO-like and MGST-like mRNA levels) and biochemical (activities of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST), and levels of glutathione (GSH), reactive oxygen species (ROS) and protein carbonyls (PCO)) components were evaluated. Further, levels of biomarkers were assessed in the gills and digestive glands of mussels. Bivalves were exposed to DCOIT (control, 0.1 μg/L and 10 μg/L) for up to 96 h. DCOIT exposure decreased GSH content in gills. Moreover, exposure to DCOIT also decreased CAT activity in the gills and digestive glands of mussels. GST activity increased in digestive gland after exposure for 24 h to both concentrations of DCOIT tested. SOD activity, ROS levels and PCO content were not affected by exposure to the contaminant. Regarding the molecular biomarkers evaluated, DCOIT exposure altered mRNA levels of SOD-like in both tissues after 24 and 96 h of exposure, and decreased MGST-like mRNA levels in the digestive gland after 96 h of exposure to the chemical. These findings suggested that exposure to DCOIT may alter the biochemical and molecular functioning of P. perna, which may harm the species.

生物结垢是一种有害现象，会给航运业造成经济损失。为防止结垢，请使用防污涂料。DCOIT（4,5-二氯-2-正辛基-4-异噻唑啉-3-酮）是许多防污涂料配方中存在的杀生物剂，对多种生物有毒。本研究的目的是评估DCOIT对褐贻贝Perna perna氧化应激指标的影响。分子（类似于SOD，GSTO和MGST的mRNA水平）和生化（超氧化物歧化酶（SOD），过氧化氢酶（CAT）和谷胱甘肽S的活性-转移酶（GST）和谷胱甘肽（GSH），活性氧（ROS）和蛋白质羰基（PCO））成分的水平进行了评估。此外，在贻贝的g和消化腺中评估了生物标志物的水平。将双壳类动物暴露于DCOIT（对照，0.1μg/ L和10μg/ L）长达96小时。DCOIT暴露会降低g中的GSH含量。此外，暴露于DCOIT还会降低贻贝the和消化腺中的CAT活性。两种浓度的DCOIT暴露24小时后，消化腺中的GST活性均增加。SOD活性，ROS水平和PCO含量不受暴露于污染物的影响。关于评估的分子生物标志物，DCOIT暴露在暴露24和96小时后会改变两个组织中SOD样的mRNA水平，并降低接触化学品96小时后，消化腺中的MGST样mRNA水平。这些发现表明，暴露于DCOIT可能会改变多年生假单胞菌的生化和分子功能，从而可能损害该物种。