A study of glycogen, lactate, total fats, protein, and glucose concentration in the liver of the frog Rana ridibunda, after exposure to cadmium for 30 days

Heavy metals such as (Cd) have been one of the most fundamental causes of soil and water pollution over the last three decades in industrial and early developed countries. We studied the impact of Cd on the liver metabolism of the frog Rana ridibunda by measuring the hepatic levels of glycogen, lactate, total fat, protein, and glucose. Liver is one of the primary target organs of Cd accumulation. Frogs were exposed for 4, 10, and 30 days in 200 mg/liter of Cd (in the form CdCl2) dissolved in water. The level of glycogen in the liver increased until Day 10, with a slight decrease at Day 30. Lactate concentration was constant until Day 10 but then increased at Day 30. Liver fat content decreased from Day 10 to Day 30. Protein concentration was elevated at Day 10 but decreased to Day 30. Cd did not affect glucose concentration during the experiment. The frog appeared to face a metabolic stress over the first 10 days of Cd exposure. At the 30th day of Cd exposure, liver metabolism appeared to return to normal conditions, most probably due to activation of the defensive mechanisms of the organism against Cd toxicity. ©