Mechanism of Cd²⁺ on DNA cleavage and Ca²⁺ on DNA repair in liver of silver crucian carp

• Published in: Fish physiology and biochemistry Vol. 34; no. 1; pp. 43 - 51
• Main Authors: Wu, Cheng, Wang, Ling, Liu, Chao, Gao, Fengqing, Su, Mingyu, Wu, Xiao, Hong, Fashui
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.03.2008; Springer Netherlands; Springer Nature B.V
• Subjects: agarose; Animal Anatomy; Animal Biochemistry; Animal Physiology; Animals; Antioxidants; apoptosis; Biomedical and Life Sciences; Cadmium; Cadmium - pharmacology; Cadmium and calcium; calcium; Calcium - pharmacology; Carassius gibelio; Carcinogenicity; catalase; deoxyribonucleases; Deoxyribonucleic acid; DNA; DNA Cleavage - drug effects; DNA damage; DNA repair; DNA Repair - drug effects; DNase activity; Enzymes - metabolism; Freshwater & Marine Ecology; gel electrophoresis; Goldfish - metabolism; Heavy metals; Histology; Life Sciences; lipid peroxidation; Lipid Peroxidation - drug effects; liver; Liver - drug effects; Liver - enzymology; Liver - metabolism; metal ions; Morphology; peroxidase; Peroxidation; reactive oxygen species; Reactive Oxygen Species - metabolism; ROS; Silver; Silver crucian carp; superoxide dismutase; Zoology; Cadmium and calcium; Silver crucian carp; DNase activity; DNA; ROS
• ISSN: 0920-1742; 1573-5168; 1573-5168
• DOI: 10.1007/s10695-007-9144-7

The subject of acute injury, apoptosis and canceration of animals induced by heavy metal ions has been one of the hotspots studied worldwide. However, the exact molecular mechanism of Cd-induced carcinogenicity remains largely unclear, and how to relieve the toxicity in vivo has rarely been reported. For this paper, we have investigated the mechanism of Cd²⁺ on DNA cleavage and Ca²⁺ on DNA repair in the liver of silver crucian carp (Carassius auratus gibelio) by agarose gel electrophoresis methods and by estimating biochemical indexes. Our results show that Cd²⁺ induces the classical laddering degradation of DNA in vivo and that DNA cleavage is repaired after injection with Ca²⁺ under various Cd²⁺ concentrations. DNA cleavage caused by Cd²⁺ is due to the activation of deoxyribonuclease (DNase) and the accumulation of reactive oxygen species (ROS). Furthermore, Cd²⁺ destroys the antioxidant system, which diminishes the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), causing an increase of the lipid peroxidation (LPO) level, respectively. However, after the liver is injected with Ca²⁺ under various Cd²⁺ concentrations, the DNase activity, the ROS generating rate and the LPO level are obviously reduced, the activities of SOD, CAT, and POD are greatly increased. At the same time, ROS production and removal recoves its balance. The results show that Ca²⁺ can relieve the toxicity of Cd²⁺ in silver crucian carp.