Wathiq Mohammed - Biology Dept. College of Science, University of Babylon, Iraq
Suad Ghali Kadhim Alahmed - Biology Dept. College of Science, University of Babylon, Iraq
Ayad M.J. Al-mamoori - Biology Dept. College of Science, University of Babylon, Iraq

This study was designed to detect the effects of lead on biochemical and molecular characteristics of common carp, Cyprenus carpio L. Two concentrations (۱۰ and ۲۰ ppm) were selected for lead respectively in one week. Biochemical markers such as acetylcholinesterase, superoxide dismutase and catalase were used to assess lead exposure cytotoxic effects, while lead-induced DNA damage was used to determine the effect of lead on molecular level. Fish samples were treated with two selected concentrations of lead solution (۱۰ and ۲۰ ppm) for one-week duration, as exposure period, to detect the impacts of lead exposure on this species.  Various biochemical markers such as acetylcholinesterase, superoxide dismutase, and catalase were applied to determine the cytotoxic impacts of lead exposure at the cellular level, while the lead-induced DNA damages were identified to reveal the influences of lead exposure at the molecular level. The results represent that the highest concentration of lead solution (۲۰ ppm) had more effects on the antioxidant enzymes activities such as superoxide dismutase (SOD) level (۶۵۵.۱۷ ± ۲۱.۷۶ mg U-۱) followed by acetyl cholinesterase and catalase (۶۵۵.۱۷ ± ۲۱.۷۶ U L-۱ and ۸۷.۹۳ ± ۷.۲۲ mg U-۱) respectively. The DNA damages were estimated by the Comet assay technique and the highest level of DNA damages were documented when lead concentration was ۲۰ ppm using different parameters of Comet assay technique such as Comet length, tail length, and tail moment (۴۰۲۱ ± ۵۶.۱۱ µL, ۵۲۳ ± ۵۵.۸۰ µL, and ۹۱.۲۰۸ ± ۹.۴۵ µL respectively). Therefore, this study confirms that the exposure to high lead concentrations would cause harmful effects on aquatic organisms at both cellular and molecular levels.

Biochemical markers, Molecular markers, Heavy metals, Common carp