Glutamate-induced calcium increase in myotubes depends on up-regulation of a sodium-dependent transporter.
We report a study on the regulation by 2-chloro adenosine (2CA) of a glutamate (Glu) transporter in myogenic C2C12 cells. Long-term 2CA exposition significantly increased the V(max) of the Glu transporter. Moreover, 2CA-treated cells responded to Glu challenge by a rapid and transient increase in their intracellular calcium level. The above reported effects were totally abolished by treating C2C12 cells with the Na(+)-dependent Glu transporter inhibitors DL-threo-b-hydroxyaspartic acid and L-trans-pyrrolidine-2,4-dicarboxylic acid. We propose that the possible link between the Glu uptake increase and the Glu induction of calcium rise could be the depolarizing currents carried by Na(+) coupled with transporter activity.
Frank
Claudio
C
Department of Pharmacology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy.
Giammarioli
Anna Maria
AM
Falzano
Loredana
L
Fiorentini
Carla
C
Rufini
Stefano
S
D015762:2-Chloroadenosine / Q000494:pharmacology; D027322:Amino Acid Transport System X-AG / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D003998:Dicarboxylic Acids / Q000494:pharmacology; D050491:Glutamate Plasma Membrane Transport Proteins; D018698:Glutamic Acid / Q000378:metabolism*; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011687:Purines / Q000378:metabolism; D011759:Pyrrolidines / Q000494:pharmacology; D027981:Symporters / Q000187:drug effects / Q000378:metabolism*; D015854:Up-Regulation
D027322:Amino Acid Transport System X-AG; D003998:Dicarboxylic Acids; D050491:Glutamate Plasma Membrane Transport Proteins; D011500:Protein Synthesis Inhibitors; D011687:Purines; D011759:Pyrrolidines; D027981:Symporters; D015762:2-Chloroadenosine; C011274:3-hydroxyaspartic acid; D001224:Aspartic Acid; D018698:Glutamic Acid; D003513:Cycloheximide; C083486:pyrrolidine-2,4-dicarboxylic acid; D002118:Calcium