Metallothionein biosynthesis as a detoxification mechanism in mercury exposure in fish, spotted scat (Scatophagus argus)

Abstract

It is of crucial importance to study on the biomarkers types to assess the specification of the pollutants and health status of marine ecosystems in environmental evaluation projects. In this respect, total metallothionein biosynthesis and mercury bioaccumulation in the liver and gills under acute mercury exposure were investigated in fish, Scat (Scatophagus argus). Spotted scat was exposed to different mercury concentrations (0, 10, 20, 30) for 24, 48, 72 h. Total MT levels were determined by enzyme-linked immunosorbent assay (ELISA) method. Mercury contents were determined through cold vapor atomic absorption spectrometry (CVAAS). Induction of MT during exposure was tissue specific, displaying different response pattern in gills and liver. Mercury accumulated in liver much higher than in gills and the latter also showed lower MT level (P<0.05). MT biosynthesis in liver showed a significant (P<0.05) increase after exposure to different mercury concentration with increase in exposure time, whereas total MT content did not significantly (P>0.05) change in gills except for 72 h exposure at 30 μg l(-1). Nonetheless, the relationship between MT biosynthesis and Mercury bioaccumulation in both tissues was significant (P<0.05). The results suggest that this form of MT in S. argus was Hg inducible and could be extended as a biomarker of mercury pollution in marine ecosystems.

Evaluation of metallothionein content in giant mudskipper Periophthalmodon schlosseri collected from west coast of Peninsular Malaysia to assess environmental metal pollution

“…The pattern of MT content in the tissues was in the decreasing order of: liver > gills > muscle.This result confirms earlier studies. The highest concentration of MT seen in the liver, is in accordance with the findings of some authors such as Tom et al [22] and Sinaie et al [60] who reported highest concentrations of MT in liver while lowest average MT was reported in muscle of Colossoma macropomum by Lemus et al [39]. High levels of copper in the liver was ascribed to copper binding to MT, which serves as a detoxification mechanism [61].…”

Biochemical and Histological Changes in Fish, Spotted Scat (Scatophagus argus) Exposed to Diazinon

“…Fish have been often used as appropriate bioindicators of chemical contaminants (Sinaie et al 2010;Tolosa et al 2005;Zuloaga et al 2009). Under conditions of stress, the body of the fish emits immediate responses recognized as primary and secondary responses.…”

Metallothionein from Wild Populations of the African Catfish Clarias gariepinus: From Sequence, Protein Expression and Metal Binding Properties to Transcriptional Biomarker of Metal Pollution

“…The plot for Hg in Figure 6 hints at seasonal differences in liver Hg levels at Kafue Flats and Kafue Town, with a trend towards lower levels in the warm-rainy season. Mercury exposure leading to MT induction has been observed previously [ 124 , 125 , 126 ]. Whilst the average values did not display statistically significant differences, it appears possible that small seasonal variations in Hg levels may be contributing to MT induction levels, and this trend should be followed up in the future.…”