Differential detoxification and antioxidant response in diverse organs of Corydoras paleatus experimentally exposed to microcystin-RR
Differential detoxification and antioxidant response in diverse organs of Corydoras paleatus experimentally exposed to microcystin-RR
复制标题
DOI：
10.1016/j.aquatox.2005.08.011
复制
发表时间：
2006-01-05
影响因子：
4.5
通讯作者：
Wunderlin, DA
中科院分区：
文献类型：
--
作者：
Cazenave, J;Bistoni, MDA;Wunderlin, DA
本文研究了溶解微囊藻毒素-RR(MC-RR)对古冠鱼肝脏、鳃、肠和脑组织中解毒酶和抗氧化酶活性以及脂质过氧化水平的影响。使用MC-RR进行剂量为0.5、2、5和10mgL-1的暴露。暴露24 h后，处死鱼，分离肝、鳃、肠、脑。通过测定谷胱甘肽还原酶(GR)、愈创木酚过氧化物酶(POD)、谷胱甘肽过氧化物酶(GPx)、过氧化氢酶(CAT)和谷胱甘肽S转移酶(GST)来评价抗氧化系统和解毒系统。此外，硫代巴比妥酸(TBA)法检测脂质过氧化(LPO)。在大多数MC-RR浓度下，所有受试器官的GST均受到抑制。L-1对肝脏中GR、POD和GPx活性有促进作用，但对鳃中GR、POD和GPx活性有抑制作用。在所研究的所有浓度下，肝脏中的CAT活性都被增强。肝脏中的抗氧化反应在低毒素浓度时被激活，随后在最高MC-RR水平时下降。相反，肝脏和大脑的解毒活性受到抑制，并呈剂量依赖关系。另一方面，MC-RR(~gt；=2ug L-1)可诱导暴露鱼脑内LPO，但对其他器官无明显影响。这一发现对这个器官的影响最大。结果显示，鳃也受到了很大的影响，因为这个组织中的抗氧化和解毒系统都受到了抑制。因此，抑制这些防御系统可能会增加暴露于溶解MC-RR的鱼类通过鳃吸收不同毒物的能力，导致鱼类健康风险增加。不同器官对MC-RR的不同反应可能与吸收途径以及不同被研究器官的生物转化和生物积累能力有关。(C)2005 Elsevier B.V.保留所有权利。
We assessed changes in activities of both detoxification and antioxidant enzymes as well as lipid peroxidation levels in liver, gill, intestine and brain of Corydoras paleatus exposed to dissolved microcystin-RR (MC-RR).Fish were captured at an unpolluted area, transported to the laboratory, and acclimated previous to experiments. Exposures were carried out using MC-RR at 0.5, 2, 5 and 10 mu g L-1. After exposures for 24 h, fish were sacrificed and dissected separating liver, gills, intestine and brain of each fish. Organs were used for enzyme extractions, evaluating both antioxidant and detoxification systems through the assay of glutathione reductase (GR), guaiacol peroxidase (POD), glutathione peroxidase (GPx), catalase (CAT) as well as glutathione S-transferase (GST). Additionally, thiobarbaturic acid (TBA) method was used to evaluate the peroxidation of lipids (LPO).GST was inhibited in all studied organs at most MC-RR concentrations used. Activities of GR, POD and GPx were enhanced in liver at 2 mu g L-1, but inhibited in gills at all tested concentrations. CAT activity was enhanced in liver at all studied concentrations.Antioxidant response in liver is activated at low toxin concentrations, followed by a drop at the highest MC-RR levels. On the contrary, detoxification activity is inhibited in liver and brain in a dose-dependent way. On the other hand, MC-RR (>= 2 mu g L-1) induced LPO in brain of exposed fish, but not in other organs. This finding becomes to this organ in one of the most severally affected.Results show that gills are also very affected, since both antioxidant and detoxification systems were inhibited in this tissue. Thus, inhibition of these defense systems could increase the uptake of different toxics through gills of fish exposed to dissolved MC-RR, leading to an increased health risk for fish.The different response observed on diverse organs exposed to MC-RR might be related to the uptake route as well as on biotransformation and bioaccumulation capabilities of different studied organs. (c) 2005 Elsevier B.V. All rights reserved.