Changes in lipid composition and lipid peroxidation products content in the freshwater mussel Anodonta cygnea L. under cadmium effect

Abstract

In order to identify specific biomarkers to cadmium-induced oxidative stress in freshwater organisms, changes in the composition of membrane and storage lipids and their fatty acids in the gills and digestive glands of freshwater mussels, Anodonta cygnea (Linnaeus, 1758), exposed to cadmium ions at 10, 50 and 100 µg/L were studied. Cadmium-induced oxidative stress was estimated by the content of lipid peroxidation products such as conjugated dienes and trienes, malondialdehyde, and Schiff bases. Accumulation of lipid peroxidation products in the gills and digestive glands reflected the intensity of lipid peroxidation, depending on the concentration and duration of cadmium exposure. Changes in the fatty acid composition of phospholipids and triacylglycerols reflected their compensatory role in the response of the mussels to the action of cadmium at various concentrations. Some indices of lipid composition (phosphatidylserine and triacylglycerol content) similarly altered under cadmium effect in both marine and freshwater mussels. The assessment of oxidative stress biomarkers and the main targets for these oxidative processes including lipids and their fatty acid composition makes it possible to identify protective biochemical mechanisms providing the high resistance of mussels to environmental pollution.