Sub-chronic impact of nickel (Ni) on glutathione peroxidase and metallothionein gene expression in Cyprinus carpio L.1785 (Common carp)

Abstract

Nickel (Ni) is considered a toxic heavy metal that causes serious diseases in humans and animals. Therefore, this study was conducted on common carp, which is considered an essential food item for humans. The present study aimed to investigate the effect of nickel exposure on the gene expression of glutathione peroxidase and metallothionein in common carp (Cyprinus carpio L.1785 (Common carp)), focusing on the effects observed after 3 and 6 weeks of exposure. The experimental fish's morphometric features were noted. All fish were stocked, regardless of gender.  Fish were subjected to varying concentrations of 20, 40, 68, 80, and 100 mg/L to obtain the LC50 for Ni during 96 hours which was 80 mg/L through 96 hours.  Additionally, the fish were exposed to two safe concentrations, 1 ppm and 5 ppm for 3 and 6 weeks. The results were as follows: Glutathione peroxidase GPX results were significantly higher in all treatment groups as compared to control groups. The treated groups exhibited higher MT concentrations than the control groups. Increased levels of glutathione peroxidase (GPX) and metallothionein (MT) gene expression indicate metal pollution and abiotic stresses in blood.