Abstract
We describe the use of the sea urchin as a model for studying efflux transporters and estimating energy cost for the cytotoxin protective system provided by these transporters. The unfertilized egg has low transport activity, which increases to a new steady state shortly after fertilization. Activity results from p-glycoprotein (p-gp) and MRP type transporters which protect the embryo from cytotoxic drugs that can disrupt cell division or induce apoptosis. The energy cost is estimated from a novel use of calcein-AM as a substrate; keeping 0.25 microM substrate levels out of the cell utilizes only 0.023% of steady state respiration.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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ATP Binding Cassette Transporter, Subfamily B, Member 1 / antagonists & inhibitors
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ATP Binding Cassette Transporter, Subfamily B, Member 1 / physiology
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Animals
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Apoptosis / drug effects
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Cell Division / drug effects
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Cyclosporins / pharmacology
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Cytotoxins / toxicity
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Embryo, Nonmammalian / cytology
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Embryo, Nonmammalian / drug effects
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Embryo, Nonmammalian / physiology*
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Energy Metabolism / drug effects
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Energy Metabolism / physiology*
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Etoposide / toxicity
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Fluoresceins / metabolism*
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Membrane Transport Proteins / drug effects
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Membrane Transport Proteins / physiology*
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Models, Animal
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Propionates / pharmacology
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Quinolines / pharmacology
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Sea Urchins
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Verapamil / toxicity
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Vinblastine / toxicity
Substances
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ATP Binding Cassette Transporter, Subfamily B, Member 1
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Cyclosporins
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Cytotoxins
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Fluoresceins
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Membrane Transport Proteins
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Propionates
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Quinolines
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calcein AM
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verlukast
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Vinblastine
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Etoposide
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Verapamil
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valspodar