PARENT SESSION
PM14 - Role of Biomarkers/Bioindicators in Ecological Risk Assessment
Monday, 18 November 2002
8:00 AM to 6:30 PM
Exhibit Hall

(P337) Effects of diesel oil on the expression and activity of P-glycoprotein in gills of the mussel Perna perna.

Bresolin, Taise¹, Trivella, Daniela¹, Lemos, Priscila¹, Marques, Marques^*,1, Bainy, Afonso¹, ¹ Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil

ABSTRACT- Some studies have reported the existence of a defense mechanism against the presence of contaminants in several aquatic invertebrates. These studies suggest that the activity of P-glycoprotein (Pgp), a membrane transporter that pumps out xenobiotics off the cell, is related with the multixenobiotic resistance (MXR). The aim of this study was to evaluate the effects of diesel oil on the expression and activity of Pgp in gill of the mussel Perna perna. Mussels were acclimatized at constant temperature, salinity and aeration for four days. The animals were exposed to diesel oil (1mL/L) for 2 hours. Pgp activity was measured in vivo (n=4) through rhodamine B (RB) accumulation in gills, using positive (RB 2.5 M; verapamil 20M) and a negative (no-verapamil) control groups. Pgp expression was evaluated by immunoblotting, according to standard protocols. No change in the Pgp expression was observed after the exposure. Contrariwise, a higher RB accumulation was seen in the exposed mussel (350g RB/g protein) compared to the control group (220g RB/g protein), showing a decrease in the Pgp activity after diesel oil treatment. Similar RB accumulation was seen in the presence of the competitive inhibitor verapamil. These results show that diesel oil may disrupt the MXR mechanism in a short-term exposure. Supported by CNPq-PSPPG and IFS.

Key words: MXR, Pgp, Perna perna, Diesel oil