Study of oxidative stress and antioxidant defense against acute mercury exposure in the bioindicator gasteropod Pomacea canaliculata.

I.A. VEGA. ; A.D. CAMPOY-DÍAZ; G. MALANGA

Congreso; XI Congreso Latinoamericano de Malacología (CLAMA); 2020

The apple snail Pomacea canaliculata has been proposed as a sentinel species of mercury pollution in freshwater bodies. Although kidney of apple snails accumulated preferentially this element, the putative mechanisms involved in the detoxification of this oxidative element have not studied yet. Here, we report the oxidative stress and oxidative defense in the snail?s kidney after exposure at a relevant ecologically Hg concentration. Adult snails were exposed 96 h to 5.5 micrograms of Hg by liter of water. Snails were sacrificed at 0, 24, 48, 72 and 96 h after exposure. Elemental concentration was analyzed by neutron activation. The oxidative stress and cellular damage were evaluated by oxidation rate of 2?7?-dichlorodihidrofluorescein Diacetate (DCFH-DA), generation of lipid radicals (LR), and carbonyl groups concentration. Non-enzymatic (β- carotene; β-C) and enzymatic (glutathione-S-transferase, GST; catalase, CAT) antioxidant defenses were also evaluated. Hg concentration increased significantly (almost three times, compared with non-exposed) after exposure (96 h), which was accompanied by an increase in the LR generation (+157%) and DCFH-DA oxidative rate (+310%). Protein carboxylation (+160%) increased throughout exposure. The β-C content and the GST enzymatic activity remained approximately constant. The CAT activity decreased between 48 and 72 h, but returned to basal levels towards 96 h. Together, these findings indicate that the Hg acute exposure generates an oxidative stress in the kidney of P. canaliculata, overcoming the antioxidant defenses of the animal and causing damage to lipids and cellular proteins