Metallothionein as Potential Biomarker of Cadmium Exposure in Persian Sturgeon (Acipenser persicus)

Abstract

Metallothionein (MT) concentration in gills, liver, and kidney tissues of Persian sturgeon (Acipenser persicus) were determined following exposure to sublethal levels of waterborne cadmium (Cd) (50, 400, and 1,000 μg l(-1)) after 1, 2, 4, and 14 days. The increases of MT from background levels were 4.6-, 3-, and 2.8-fold for kidney, liver, and gills, respectively. The results showed that MT level change in the kidney is time and concentration dependent. Also, cortisol measurement revealed elevation at the day 1 of exposure and followed by MT increase in the liver. Cd concentrations in the cytosol of experimental tissues were measured, and the results indicated that Cd levels in the cytosol of liver, kidney, and gills increased 240.71-, 32.05-, and 40.16-fold, respectively, 14 days after exposure to 1,000 μg l(-1) Cd. The accumulation of Cd in cytosol of tissues is in the order of liver > gills > kidney. Pearson correlation coefficients showed that the MT content in kidney is correlated with Cd concentration, the value of which is more than in liver and gills. Thus, kidney can be considered as a tissue indicator in A. persicus for waterborne Cd contamination.

Research Article Cadmium accumulation and metallothionein gene expression in the liver of swamp eel (Monopterus albus) collected from the Mae Sot District, Tak Province, Thailand.

“…The current study revealed that the lowest expression of 0.48-fold (compared to S1) was found in S4, which turned out to be the highest hepatic Cd level site. This is in agreement with the findings of Shariati et al (2011) who found that the Cd levels in the liver of Persian sturgeon increased as the Cd concentration and time exposure increased; however, MT protein level increased only in short period (4 days) after being exposed to Cd, and there was no significant change of MT protein level between 4-and 14-day treatment groups. The accumulations of Cd in the liver might exceed its regulation capacity, leading to disruption in the induction of MT synthesis and eventually loss of the correlation between MT and Cd levels as found at lower exposed concentrations (Shariati et al, 2011).…”

“…This is in agreement with the findings of Shariati et al (2011) who found that the Cd levels in the liver of Persian sturgeon increased as the Cd concentration and time exposure increased; however, MT protein level increased only in short period (4 days) after being exposed to Cd, and there was no significant change of MT protein level between 4-and 14-day treatment groups. The accumulations of Cd in the liver might exceed its regulation capacity, leading to disruption in the induction of MT synthesis and eventually loss of the correlation between MT and Cd levels as found at lower exposed concentrations (Shariati et al, 2011). When the metal level has surpassed the capability of an animal to produce MT, the metal may bind to high molecular mass proteins, but with a weaker affinity than the Cd toxicity may follow (De Boeck et al, 2003).…”

Heavy Metal-induced Metallothionein Expression Is Regulated by Specific Protein Phosphatase 2A Complexes

“…Moreover, the studies conducted in MT transgenic mice or MT-null mice models provide strong evidence that MTs play an essential role in protecting cells from acute heavy metal poisoning (15)(16)(17)(18). It is evident that MTs can be a useful biomarker for the prediction of heavy metal toxicity and adverse biological outcome (19,20).…”

Cloning metallothionein gene in Zacco platypus and its potential as an exposure biomarker against cadmium

“…In previous studies, the 48-h exposure to Cd concentrations of 50 and 367 μg/L induced mRNA expression of MT in Persian sturgeon (Acipenser persicus) and Korean spotted barbell (Hemibarbus mylodon), respectively (Cho et al 2008;Shariati et al 2011). For yellow catfish (P. fulvidraco), significant enhancement of hepatic MT transcription was reported at 6 h of exposure to 5 mg/L Cd (Kim et al 2012).…”