Comparative Biochemistry and Physiology Part C 135 (2003) 295–303 1532-0456/03/$ - see front matter  2003 Elsevier Inc. All rights reserved. doi:10.1016/S1532-0456(03)00117-0 DNA damage in digestive gland and mantle tissue of the mussel Perna perna Eduardo Alves de Almeida , Sabrina de Almeida Marques , Clecio Fernando Klitzke , a a a ´ Afonso Celso Dias Bainy , Marisa Helena Gennari de Medeiros , Paolo Di Mascio , b a a Ana Paula de Melo Loureiro * a, Departamento de Bioquımica, Instituto de Quımica, Universidade de Sao Paulo, CP 26.077, Av. Prof. Lineu Prestes 748, Sao Paulo, a ´ ´ ˜ ˜ SP, CEP 05513-970 Brazil Departamento de Bioquımica, Centro de Ciencias Biologicas, Universidade Federal de Santa Catarina, Florianopolis, SC, Brazil b ´ ˆ ´ ´ Received 11 March 2003; received in revised form 26 May 2003; accepted 27 May 2003 Abstract Data concerning the susceptibility of DNA to damage by reactive oxygen and nitrogen species and other endogenous compounds produced by physiological stress in marine organisms is lacking, especially in bivalve mollusks. In this article, we analyzed the background levels of lipid peroxidation (malondialdehyde, MDA), 8-oxo-7,8-dihydro-29- deoxyguanosine (8-oxodGuo) and 1,N -etheno-29-deoxyguanosine (1,N -´dGuo) in digestive gland and mantle tissue of 2 2 mussels Perna perna collected at a cultivation zone in Florianopolis (Santa Catarina, Brazil). The present data point to ´ the possibility of the use of both 8-oxodGuo and 1,N -´dGuo as complementary indicators of oxidative stress processes 2 in mussels. A sensitive method coupling high performance liquid chromatography to mass spectrometry was applied for the detection of 1,N -´dGuo in mussel tissues. 2  2003 Elsevier Inc. All rights reserved. Keywords: DNA damage; 8-oxodGuo; Etheno adduct; Lipid peroxidation; Mussel; Oxidative stress; Perna perna; Mass spectrometry; HPLC 1. Introduction Reactive oxygen and nitrogen species (ROSy RNS) are continuously generated in biological systems as by-products of oxidative metabolism. A failure to remove these ROSyRNS by antioxi- dant defense mechanisms can result in damage to key macromolecules, in particular DNA, lipids and proteins (Lemaire and Livingstone, 1993; Halli- well, 1993). *Corresponding author. Tel.: q55-11-3091-2153; fax: q55- 11-3091-2186. E-mail address: anapaula@iq.usp.br (A.P. de Melo Loureiro). The maintenance of DNA integrity is of para- mount importance to all organisms. For this reason, living organisms possess very efficient and intri- cate mechanisms for the protection of their genetic material. Significant stress eventually results in the dysfunction of these mechanisms and an increase in DNA damage occurs (Steinert, 1999). Thus, the assessment of such DNA lesions in organisms could improve fundamental information about their physiological status. Much work has been focused on DNA damage as a consequence of DNA susceptibility to ROSy RNS. The oxidation of DNA can produce a number of different modified bases, including 8-oxo-7,8-