Multidrug
resistance in the embryos and larvae of the mussel Mytilus edulis
I. McFadzen, N. Eufemia, C. Heath, D. Epel, M. Moore,
D. Lowe-2000
Marie Environmental
Research, 50 (1-5) : 319-323 (from
Current Contents)
Abstract :
Cells exhibiting the multidrug resistance (MDR)
phenotype demonstrate a decreased intracellular drug accumulation due to an
active outward transport and decreased intracellular flux. This study
demonstrates the inhibition of MDR in mussel (Mytilus edulis) embryos and
larvae based on a simple bioassay. The development of embryos was assessed
and abnormalities identified at key stages of development, including
gastrulation, trochophore and prodissoconch stages. The incidence of
developmental abnormalities was significantly increased in the presence of
vinblastine, MMS, chloroquine, mitomycin-C, cadmium chloride and colchicine,
compared to clean seawater. Consistently, there was a further increase in
the number and severity of deformities observed when each toxin was added in
the presence of verapamil. Larval growth was also significantly impaired in
the presence of verapamil. Increased accumulation of fluorescent MDR dyes,
such as rhodamine B, has been measured and shown to be verapamil sensitive.
This bioassay encompasses a period of intense cellular activity during which
the impairment of a number of critical processes results in abnormal growth
and development.
(Plymouth Marine Lab, CCMS, Prospect Pl,Hoe, Plymouth
PL1 3DH, Devon, England, UK, e-mail : irbm@wpo.nerc.ac.uk)
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