Variability of filtration and food assimilation rates, respiratory activity and multixenobiotic resistance (MXR) mechanism in the mussel Perna perna under lead influence

Abstract

The economic importance that myticulture is conquering in Santa Catarina State (South of Brazil) explains the crescent search for new coastal sites for farming. Physiological and biochemical studies of the mussel Perna perna are important to the establishment of methodologies for program assessment and environmental monitoring, allowing to infer about site quality and possible influences of xenobiotic agents on coastal areas. In order to evaluate effects caused by lead poisoning (1.21 µmol.L -1 ), the mussels were maintained at constant temperature (25 o C) and fed with Chaetoceros gracilis for 15 days. The control group was acclimatized in sea water 30‰. At the end of this period time, physiological measurements were carried out along with statistic analysis for filtration rates, lead assimilation and overall respiratory activity. The mechanism of multixenobiotic resistance (MXR) was particularly evaluated in standardized gill fragments using rhodamine B accumulation and its quantification under fluorescence optical microscopy. Regarding the control group, results had shown that the mussels maintenance in a lead-poisoned environment caused higher filtration rates (1.04 and 2.3 and L.h -1 .g -1 ; p < 0.05) and lower assimilation rates (71.96% and 54.1%, respectively). Also it was confirmed a lesser rhodamine B accumulation in the assays under influence of lead, suggesting that this metal induces the MXR mechanism expression in mussel P. perna. These results indicate that such physiological and biochemical alterations in the mussels can modify the energy fluxes of its metabolism, resulting in possible problems on the coastal systems used as cultivating sites.Key words: physiological parameters, multixenobiotic resistance mechanism, MXR, Perna perna, lead. RESUMOVariabilidade das taxas de filtração, assimilação e respiração e do mecanismo de resistência a multixenobióticos (MXR) no mexilhão Perna perna sob influência do chumbo A importância sócio-econômica que a mitilicultura conquistou no Estado de Santa Catarina explica a crescente procura por novos sítios costeiros para o seu uso. Estudos fisiológicos e bioquímicos do mexilhão Perna perna se apresentam como metodologias viáveis para programas de avaliação e monitoramento ambiental, permitindo inferir sobre a qualidade dos sítios e possíveis influências de agentes xenobióticos nas áreas costeiras. Com o objetivo de determinar a existência de variabilidade nesses parâmetros evocada pelo chumbo (1.21 µmol.L -1 ), mexilhões Perna perna foram mantidos à temperatura constante e alimentados com Chaetoceros gracilis por 15 dias. O grupo controle foi aclimatado em água do mar a 30‰. No final desse período foram realizados experimentos estáticos fisiológicos de filtração, respiração e assimilação, Braz. J. Biol., 62(4A)

Catalase Activity in Brown Mussels (Perna perna) under Acute Cadmium, Lead, and Copper Exposure and Depuration Tests

“…In this paper, an induction of CAT observed in the tissues exposed to cadmium, lead, and copper suggests greater utilization of CAT in order to combat metals present in these marine media. Moreover, lead alters filtration and assimilation rates [39], changes expression of stress proteins [40], and decreases immunity in mussels [41]. In addition, lead binds with glutathione and decreases GSH level [42].…”

Physiological energetics of the brown mussel Perna perna (L.) transplanted in the Itajaí-Açu river mouth, Southern Brazil

“…According to Pessatti et al (2002), sub-lethal concentrations of Pb could stimulate the CR and inhibit the RR of P. perna, however, under conditions where other trace metals are also present and/or with longer exposure times the CR may be inhibited (Resgalla and Moraes 2008).…”

Chemosensitizer effect of the crude oil water solution fraction on multixenobiotic resistance mechanism of the mussel <i>Perna perna</i> exposed to tributyltin

“…1). As the gender does not modify the standard activity of MXR complex (Pessatti et al, 2002), both male and female individuals were used. After sampling, the animals were washed and kept in aquaria (2.5 individuals per liter) for acclimatization for at least five days, in filtered seawater, before the experiments.…”

“…The mechanism of MXR efflux was determined according to Cornwall et al (1995) with the modifications proposed by Pessatti et al (2002). The gills were sampled after the anesthesia of mussels on ice and transferred to filtered sea water.…”

“…These compounds can block the function of transport activity, decreasing the capacity of efflux xenobiotics or endogenous compounds from the cell (Kurelec, 1992;Achard et al, 2004;Zaja et al, 2008). To the study of this transport activity, have been intensively used substrates fluorophores of the MXR, among which the rhodamine B (Cornwall et al, 1995;Pessatti et al, 2002), which can be used as a marker as much accumulated as effluxed.…”