Effects of Mercury, Chromium and Nickel on Glycogen Reserves and Protein Levels in Tissues of Cyprinus carpio

Authors: Mustafa CANLI

Abstract: The carps Cyprinus carpio were exposed to sublethal concentrations of mercury (0.01 and 0.1 mg/1), chromium (2 and 20 mg/1) and nickel (2 and 20 mg/1) for seven days. Following the metal exposures, total and heat-stable protein levels in the liver, muscle and gill and glycogen contents in the liver and muscle of fish were measured. Results were statistically compared with a control group which was kept in the same conditions without any metal addition. Glycogen levels in the tissues of all metal-exposed carps significantly decreased. When compared to the control levels, mercury caused highest depletions of glycogen in the tissues (up to 96 %), and was followed by nickel (up to 86 %) and chromium (up to 75 %). Total protein contents in the tissues of metal-exposed animals decreased significantly over control values, except in the liver and gill of chromium exposed animals. In the heat-treated homogenates, percent protein loss differed between control and metal-exposed fish. Highest protein loss after the heat-treatment occurred in chromium exposed fish (up to 84 %), and it was followed by nickel (up to 43 %), mercury (up to 41 %) and control (up to 33 %) fish. Except in the chromium experiment, highest percentages of protein loss were found in the muscle, and were followed by the liver and gill.

Keywords: Mercury, Chromium, Nickel, Protein, Glycogen