en Toxicology Toxicology پژوهشي Orginal research papers <span style="font-size:11pt"><span style="line-height:120%"><span style="text-autospace:none"><span sans-serif="" style="font-family:Calibri,"><span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">This study is performed to investigate the effects of water-borne Ni²⁺ on common carp (<i>Cyprinus carpio</i>) liver and bone metabolisms. Fish (<i>N</i>=60; 184.40&plusmn;18.56g) were exposed to background concentrations of Ni²⁺ (based on measured LC₅₀-96h: 5.820 mg/L), including 0.058, 0.291, 0.580, 1.750, 2.910 mg/L for 30 continuous days. Ni²⁺-exposed fish showed a rising trend in the case of serum aspartate transaminase (AST). Serum alkaline phosphatase (ALP) elevated (<i>p</i><0.05) in all Ni²⁺treatments. Serum total protein, globulin, and albumin showed a transient reduction in 0.058, 0.291 and 0.580 mg/LNi²⁺ exposures (<i>p</i><0.05). Although serum calcium level did not change significantly, serum inorganic phosphorus was elevated (<i>p</i><0.05) in 0.580 mg/LNi²⁺. Bone isoenzyme of ALP observed in higher levels in all Ni²⁺treatments than the control group (<i>p</i><0.05). Pathological damages, such as focal necrosis, pycnosis and cytoplasm degeneration were observed in liver tissues of Ni²⁺-exposed fish. A higher number of osteocytes as well as osteoclasts in bone of Ni²⁺-exposed fish revealed dual effect of this metal in the case of bone metabolism. Generally, low level of nickel had no significant effect on metabolic parameters of liver and bone while highest nickel treatment had adverse effects, reflecting dual effects of this metal on carp.</span></span></span></span></span></span></span></span> Nickel, Common carp, Liver histopathology, Bone histology, Blood chemistry 526 546 http://jifro.ir/browse.php?a_code=A-10-1953-10&slc_lang=en&sid=1 P. Bozorgzadeh pouryabozorgzadeh@gmail.com 100319475328460049002 100319475328460049002 No Department of Fisheries, Science and Research Branch, Islamic Azad University, Tehran, Iran M. Shamsaie Mehrgan drshamsaie@gmail.com 100319475328460049003 100319475328460049003 Yes Department of Fisheries, Science and Research Branch, Islamic Azad University, Tehran, Iran N. Pourang 100319475328460049004 100319475328460049004 No Iranian Fisheries Science Research Institute S.P. Hosseini Shekarabi hosseini.pezhman@yahoo.com 100319475328460049005 100319475328460049005 No Department of Fisheries, Science and Research Branch, Islamic Azad University, Tehran, Iran