Hindawi Publishing Corporation Journal of Toxicology Volume 2010, Article ID 407360, 9 pages doi:10.1155/2010/407360 Research Article Metallothionein-Like Proteins and Energy Reserve Levels after Ni and Pb Exposure in the Pacific White Prawn Penaeus vannamei Gabriel Nunez-Nogueira, 1 Catherine Mouneyrac, 2, 3 Alice Muntz, 2, 3 and Laura Fernandez-Bringas 1 1 Unidad Academica Geolog´ ıa Marina y Ambiental, Instituto de Ciencias del Mar y Limnolog´ ıa, Universidad Nacional Aut´ onoma de M´ exico, M´ exico 04510, DF, Mexico 2 MMS, EA2160, Facult´ e de Pharmacie, Universit´ e de Nantes, 1 rue G. Veil, BP 53508, 44035 Nantes Cedex 1, France 3 Institut de Biologie et d’Ecologie Appliqu´ ee, CEREA, Universit´ e Catholique de l’Ouest, 3 Place Andr´ e Leroy, 49008 Angers, France Correspondence should be addressed to Gabriel Nunez-Nogueira, gnunez@cmarl.unam.mx Received 13 January 2010; Revised 3 June 2010; Accepted 7 July 2010 Academic Editor: Anthony DeCaprio Copyright © 2010 Gabriel Nunez-Nogueira et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This study analyzed the changes in metallothionein-like proteins (MTLPs) and Energy Reserves (ERs) in hepatopancreas and abdominal muscle of the white prawn Penaeus vannamei. Realistic metal concentration exposure for 10 days to Ni and Pb in solution revealed that juvenile prawns partially induce MTLP in hepatopancreas after Pb exposure. Ni was distributed equally between soluble and insoluble fractions, while Pb was present only in the insoluble fraction, suggesting different detoxification strategy. No changes in lipids and glycogen concentration were detected under these experimental conditions in both tissues analyzed. MTLP could not be considered as a suitable indicator for lead exposure in hepatopancreas. 1. Introduction Penaeid prawns are important subjects of mariculture and coastal fisheries activities throughout the tropics and subtropics [1–3]. Traditionally, prawn farms located near the coast used directly coastal seawater to rear the prawns without additional processes. Shrimp culture is therefore potentially affected by anthropogenic activities including metal contamination. Specifically in coastal Mexican waters, a great number of basic metal industries represent the mainly heavy metal (cadmium, lead, nickel, chromium, etc.) source [4–9]. Penaeid prawns have revealed great capacity to accumulate and take up metals from solution, either essential or not essential elements and yet survive in these polluted environments [10–14]. Consequently, metals are subsequently potentially transferred to man through the food chain. Thus, it is of great concern to investigate detox- ificatory processes involved in prawns exposed to metals. It is well known that the induction of metallothionein which is a cystein-rich protein and has detoxifying properties, occurs in aquatic invertebrates after in situ or laboratory metal exposure (for review see Amiard et al. [15] and literature cited therein). Moreover, physiological markers reflecting the energetics of an organism may contribute to the understanding of the mode of the toxicant [16–18]. The “Metabolic cost” hypothesis suggests that toxic stress induces metabolic changes which may lead to a depletion of its energy reserves resulting in adverse effects on growth and reproduction [19]. Comprehension of the mechanisms related to the sublethal effects caused by toxic metals upon shrimp metabolism would help to develop sensitive and diagnostic tools (biomarkers) with a predictable capacity in assessing the toxic effects, thus contributing to better coastal seawater management and sustainable aquaculture. This study is part of a wider investigation of the regulation and accumulation of the trace metals nickel and lead in a penaeid prawn Penaeus vannamei [20]; metals previously detected in coastal Mexican waters [4–8]. Nickel has occasionally been interpreted as an essential metal [21, 22], probably as a consequence of its ability to be substituted for other divalent metal ions, particularly zinc, or as a part of an enzymatic structure [23, 24].