B. Kurelec et al., EXPRESSION OF MULTIXENOBIOTIC RESISTANCE MECHANISM IN A MARINE MUSSELMYTILUS-GALLOPROVINCIALIS AS A BIOMARKER OF EXPOSURE TO POLLUTED ENVIRONMENTS, Comparative biochemistry and physiology. Part C, Pharmacology toxicology & endocrinology, 113(2), 1996, pp. 283-289
The gills of mussel Mytilus galloprovincialis express a multixenobioti
c resistance mechanism (MXRM) mediated by P-glycoprotein activity, as
evidenced by the rate of (G-H-3)vincristine accumulation and its sensi
tivity to verapamil, as well as by the direct immunochemical detection
of P-glycoprotein by Western blotting analysis. The MXRM is induced a
t polluted sites: gills from mussels living at polluted sites accumula
te less vincristine, the vincristine accumulation is less sensitive to
verapamil, and in most cases express higher levels of P-glycoprotein.
The state of induction of functional activity of MXRM is proportional
to the level of pollution, as demonstrated at sites along the well de
fined pollution gradient in the aquatorium of Rovinj, Northern Adriati
c. Since the immunological expression of P-glycoprotein may be comprom
ised by high interindividual differences, season, and some as yet unkn
own factors, it could not be used as a single marker of exposure. Howe
ver, the rate of vincristine accumulation and its sensitivity to verap
amil offer a new, informatively powerful, molecular biomarker of expos
ure.