Keywords: 
• di-(2-ethylhexyl) phthalate /
• Cyprinus carpio Linnaeus /
• kidney /
• brain /
• biochemical marker /
• immunotoxicity /
• neurotoxicity

Abstract: In order to investigate the effect of DEHP (di-(2-ethylhexyl) phthalate) on the biochemical markers of kidney and brain in Cyprinus carpio (C. carpio), a 20-day period of experiment was conducted at four experimental concentrations of 5, 20, 80 and 160 mg·L^-1. H₂O and Tween-80 were used as the controls respectively. The results showed that, when compared with the H₂O control, all indexes of the Tween-80 control showed no significantly difference. While compared with the two controls, with the increasing of DEHP, the activities of the superoxide dismutase (SOD), catalase (CAT), resisting superoxide anion (·O^2-) and scavenging hydroxyl free radical (·OH^-) were all decreased significantly (P<0.05 or P<0.01) in the kidney. The activities of the glutathione peroxidase (GSH-Px) was increased first and then decreased, especially in the groups 5, 20, 80 mg·L^-1 (P<0.05). The malonaldehyde (MDA) increased remarkably in the groups of 80,160 mg·L^-1 in the kidney, but it showed no significantly differences in the brain. What is more, in the brain, the activity of nitric oxide synthase (NOS) was increased significantly in all the experimental groups (P<0.05 or P<0.01). On the contrary, the acetylcholinesterase (AChE) activity was significantly inhibited in the groups including 80, 160 mg·L^-1 DEHP (P<0.05). With the increasing of DEHP, the calcineurin (CaN) activity was increased first and then decreased. It increased significantly in 20 mg·L^-1 (P<0.01) and decreased remarkably when the dose were 80, 160 mg·L^-1 (P<0.01). Both resisting superoxide anion (·O^2-) and scavenging hydroxyl free radical (·OH^-) were decreased remarkably (P<0.05 or P<0.01). These results suggested that DEHP imposes immune toxicity and neurotoxicity to carp in the range of the experimental concentrations. The influence mechanism will need to be researched.