Proportioning of Biomarkers (GSH, GST, Ache, Catalase) Indicator of Pollution at Gambusia affinis (Teleostei Fish) Exposed to Cadmium

摘要

In this experimental study we were interested in cadmium, a heavy metal frequently met in the watery ecosystems located in residential and industrialized areas. This research aims at evaluating the impact of cadmium, diluted with various amounts (0.1, 1 and 5 μg L 1) in the water of various batches of Gambusia affinis, by the proportioning of certain biomarkers indicator of pollution: the GSH, the GST, the catalase (on the level of the liver) and the acetylcholinesterase (on the level of the brain). The lethal concentrations (100% of mortalities) are equal to 10 cadmium μg L 1. The results of proportionings show that the contents of the biomarkers vary according to the amount and from the exposure time to cadmium. The exposure of fish to 5 cadmium μg L 1 causes an activation of the system of detoxification which is translated, as from the 7th day of exposure, by the reduction in the rate of GSH and the increase in the activity of the GST. The activity of the hepatic GST presents a significant and very significant difference in fish exposed during 15 days to the respective amounts of 1 μg L 1 and 5 cadmium μg L 1. With regard to the catalase of the falls of the content are raised at the 7th day of exposure at the unit of the batches treated with cadmium. As for the acetylcholinesterase it is in fish exposed to 5 μg L 1 during more than 15 days that a significant difference is observed.