SEASONAL VARIATION OF BIOCHEMICAL AND ANTIOXIDANT PARAMETERS IN SCALLOP Pecten jacobaeus TISSUES

The present study describes  levels and relationships of biochemical parameters  (calcium - Ca, magnesium - Mg, glucose - GLU, trigylceride - TRIG, cholesterol - CHOL,  lactate dehydrogenase - LDH),   )  and activity of oxidative damage defense system  (total antioxidative status - TAS, superoxid dismutase - SOD, glutathione peroxidase - GPx, lipid peroxidation - measured as thiobarbituric acid reactive substances - TBARS) over seasons in Mediterranean scallop (Pecten jacobaeus L.) tissues. In general, levels of Ca, Mg, GLU, TRIG, CHOL, TAS and TBARS were predominate in digestive gland and gonad  and LDH in muscle.  In  digestive gland, muscle and gills concentrations of Ca, Mg, GLU, TRIG and CHOL were higher during autumn and winter periods that coincide with the peak seasons for diatoms and coccolithohorids, species serving as food for the scallop. In gonadal tissue lower values detected in spring and autumn could be related to spawning activity. Higher LDH acitivity in muscle and digestive gland were observed during summer and autumn and it was complete ly absent in gonad and gills.  The seasonal variation of antioxidant enzyme activites  (GPx and SOD) was inversly related for TAS and TBARS. TBARS  and TAS  were increased in winter with significantly higher values in digestive gland . W inter  TAS  maxima indicate increase  of antioxidants of nonenzymatic nature such as low-molecular-weight compounds (e.g. carotenoids) during cold months. A ctivities  of SOD and GPx  were  manyfold  higher in  muscle, gills and gonad (especially in spring and summer) compared to digestive gland  and  could be attributed to the  increased metabolic rates during breeding season as well as physicochemical properties of seawater.