(full paper is archived in the Miller Library)
Title: Induction of the multidrug-resistance protein in the mussel Mytilus californianus
Student Author(s): Shaevitz, Marejka H.
Faculty Advisor(s): Epel, David
Location: Final Papers Biology 175H
Date: June 1996
Abstract: Mussels of the species, Mytilus californianus, are known to have a multidrug-resistance transport protein (p-glycoprotein, MDR) analogous to the multidrug resistance protein found in many human tumor cell lines, which protectively transports a wide range of moderately hydrophobic and potentially toxic compounds out of cells. Previous studies have suggested the transporter may be inducible by exposure to environmental toxins. The present study examined whether exposure to toxic compounds would induce mussels to increase synthesis or activity of p-glycoprotein. After exposing animals for 1-3 weeks to two model genotoxic compounds, 2-Acetylaminofluorene and 3-Methylcholanthrene, gill tissues were analyzed by Western Blot to quantify protein levels. In addition, two assays analyzing the efflux rates of a fluorescent p-glycoprotein substrate were employed in order to study the kinetics of the transporter's activity. Results of the kinetics assays showed no significant difference between control organisms and exposed organisms in rates of efflux of the fluorescent substrate (ANCOVA: p=0.924, p=0.357). Western analyses to date have been inconclusive. Thus, this study does not show significant inductive effects of exposures to non-lethal levels of genotoxin.