Artigo -cádmio

CADMIUM TOXIC EFFECTS ON HEART VENTRICLE OF HALOBATRACHUS DIDACTYLUS– CHRONIC EXPOSURE STUDY Natércia Joaquim CCMar, Universidade do Algarve, Campus de Gambelas, 8000-810 Faro, PORTUGAL Phone: [phone]; Fax: [phone]; E-mail: [e-mail] Andrea Sousa, Rui Serrano, Vera Correia, Josefina Coucelo, José Coucelo

EXTENDED ABSTRACT ONLY – DO NOT CITE Introduction Due to its potential as a toxic substance, cadmium is one of the metals to which a special statute in questions of environmental and health is given. As no biological function has been attributed to cadmium, this metal is toxic for the cell, even in low concentrations. Various studies connect cadmium with oxidative stress, since this metal can alter the antioxidant defence system in several tissues of several animals, causing a depletion in the levels of reduced glutathione, as well as an alteration in the activity of antioxidant enzymes, and a change in the structure of the cellular membrane through a process of lipid peroxidation (Jamall et al., 1989; Palace et al., 1993; Sarkar et al., 1995; Zikic et al., 1996). Cadmium has a high potential of toxicity, mainly in the liver and kidney. However, its interaction with the cardiac muscle cell is not well understood. The objective of this work was to analyse antioxidant defence system responses induced by a chronic exposure to a sub-lethal cadmium concentration (1 mg/kg), on heart ventricle of a teleost fish, Halobatrachus didactylus (toadfish).

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Materials and Methods H. didactylus individuals were collected from Ria Formosa (South Coast of Portugal) and divided into two groups: Control group (CTRL), injected intraperitoneously (i.p.) at day 0 with 0.9% NaCl, and sacrificed after 6 weeks; Cadmium exposure group (Cd), injected i.p. at day 0 with 1 mg/kg of Cd as CdCl2 in NaCl 0.9%, and sacrificed after 6 weeks of exposure. Heart ventricle from each individual was collected after sacrifice and cytosolic and mitochondrial fractions were