Synergy occurs when chemicals give pronounced effect on combination in contrast to their individual effect. The objective of this study was to investigate the synergistic effect of pesticides carbaryl (C) and methyl parathion (MP) on oxidative stress biomarkers viz catalase (CAT), glutathione reductase (GSSG-R) including different enzymes like lactate dehydrogenase (LDH), succinate dehydrogenase (SDH) and acetyl cholinesterase (AChE) in different tissues of carps Catla catla. Fishes were exposed to 6.25 mg/L of MP and 2.3 mg/L of C in mixture (one-third of LC50 value). CAT and GSSG-R were studied in gills, brain, liver and muscle of carp were found to be elevated significantly (p < 0.005). LDH activity increased significantly (p < 0.005) in synergistic group, there was a seven-fold (748%) increase in LDH activity in muscle compared to individual studies with same pesticides. Contrary to LDH, sudden decrease in SDH activity was accounted. Significant (p < 0.005) decrease in AChE activity after initial 24 h was remarkable addressing to the shift in neurotransmission pathway in organism. Significant increase was observed in activity of CAT and GSSG-R in all tissues compared to control fishes in individual as well as synergistic (MP + C) group suggesting that CAT and GSSG-R can be a potential biomarker of oxidative stress when studied in combination.

中文翻译：

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谷胱甘肽还原酶和过氧化氢酶是鱼中农药协同中毒的潜在生物标志物。

当化学品对它们的单独作用产生明显的影响时，就会产生协同作用。这项研究的目的是研究农药西维因（C）和甲基对硫磷（MP）对氧化应激生物标记物过氧化氢酶（CAT），谷胱甘肽还原酶（GSSG-R）的协同作用，其中包括乳酸脱氢酶（LDH）等不同的酶，鲤鱼Catla catla不同组织中的琥珀酸脱氢酶（SDH）和乙酰胆碱酯酶（AChE）。鱼类暴露于混合物中6.25 mg / L的MP和2.3 mg / L的C（LC50值的三分之一）。在in中研究了CAT和GSSG-R，发现鲤鱼的脑，肝和肌肉显着升高（p <0.005）。协同组的LDH活性显着增加（p <0.005），与使用相同农药的个别研究相比，肌肉中LDH活性增加了七倍（748％）。与LDH相反，导致SDH活性突然下降。在最初的24小时后，AChE活性显着下降（p <0.005），这显着地解决了生物体内神经传递途径的转变。与单独和协同（MP + C）组的对照组鱼相比，在所有组织中CAT和GSSG-R的活性均显着增加，这表明当组合研究时，CAT和GSSG-R可能是氧化应激的潜在生物标志物。