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To reveal a potential combined effect of pollution and continuos warming towards freshwater organisms, the molecular responses of stress and toxicity were compared during two years in the bivalve mollusks Anodonta anatina from the cooling pond of Khmelnytskyi Nuclear Power Plant (N-group) and from the ponds in the forestry (F-group) and agricultural (A-group) areas. Using Classification and Regression Tree (CART) software on the basis of a set of studied markers, characteristics for the distinguishing of N-group were selected. Firstly, it was the constantly elevated level of the vitellogenin-like protein in gonads and hemolymph of male specimens that witness the effect of endocrine disruption. The mussels of N-group demonstrated on oxidative injury with highest values of the Index of inter-seasonal variability for oxidized glutathione and metallothionein-related thiols among three groups, and constantly high level of apoptotic activity in the digestive gland. Remarkably higher levels of copper and cadmium within the tissues were detected in the N-group reflecting the industrial pollution. These metals were preferentially bound to metal-buffering protein metallothionein. A combination of these characteristics demon­strates that stable elevated temperature jointly with industrial pollution caused a partial apoptotic elimination of cells with the nuclear lesions and provoked the exceeding of resistance of stress-related responses and reproduction-related functions in the mussels.

The effect of metal-nanocomposites (Me-NC) of cobalt and zinc (Co- and Zn-NC, correspondingly) synthecized on the basis of vinylpyrrolidone (PS) on the metal-accumulative proteins with antioxidant potential metallothioneins (MT) in crucian carp (Carassius auratus gibelio) was studied­. Fish was subjected to the effect of Co-NC, Zn-NC, Co2+, Zn2+ or polymer carrier (PC) in the concentrations correspondent to 50 µg×Co/l or 100 µg×Zn/l during 14 days. It was shown that the MTs response is highly specific for the nature of metal, both in ion and Me-NC form: the effect of Co and Co-NC provoked the elevation of total MT concentration (MT-SH) and activation of antioxidant defence, whereas Zn and Zn-NC induced the decrease of the concentration of MT-SH and the inhibition of antioxidant defense. All the exposures provoked the decrease of the concentration of immunoreactive chelating MT form (MTi) and reduced glutathione, activation of anaerobiosys and Mn-superoxide dismutase, and also decrease of the concentration of proteins and lipids oxidative injury products. It was accompanied by the increase of the content of erythrocytes with nuclear abnormalities but did not cause the decrease of choline esterase activity. According to the rate of MT-SH and MTi concentrations, antioxidant potential of MTs is determined by its apoform. Our data indicate that partial biodegradation of Me-NC occurs in the organism of crucian carp.