Pentobarbital and brilliant green modulate the current response of recombinant rat kainate-type GluR6 receptor channels differentially.
Kainate-type receptor channels (GluR5-7, KA1,2) belong to the family of ionotropic glutamate receptor channels. In the present study we tested the interaction of two different drugs with GluR6 channels using outside-out patches from HEK cells transiently transfected with cDNA of GluR6 channels. Glutamate and the respective drugs were delivered by a system for ultrafast solution exchange. Application of a saturating concentration of 3 mM glutamate resulted in fast current transients with desensitization time constants between 3 and 10 ms. Addition of pentobarbital (>or=1 mM) to the 3 mM glutamate containing test-solution resulted in a significant decrease of the time constant of current decay without affecting the peak current amplitude. Brilliant green (>or=1 mM) had the opposite effect and led to an increase of the time constant of current decay after application of 3 mM glutamate. The pharmacological effects of both drugs were completely reversible. Additionally, a significant increase of the peak current amplitude and the time constant of deactivation in presence of brilliant green was observed. Summarizing our results, we could identify a further substance, brilliant green, interacting with GluR6 kainate-type receptor channels.
Bufler
J
J
Neurological Department of the Medical School Hannover, 30623 Hannover, Germany. bufler.johannes@mh-hannover.de
Cordes
A
A
Heineke
W
W
Dengler
R
R
Krampfl
K
K
D002478:Cells, Cultured / Q000187:drug effects / Q000502:physiology; D002490:Central Nervous System / Q000187:drug effects / Q000502:physiology; D004396:Coloring Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions / Q000502:physiology; D018757:GABA Modulators / Q000494:pharmacology*; D018698:Glutamic Acid / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D010424:Pentobarbital / Q000494:pharmacology*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D018092:Kainic Acid Receptors / Q000187:drug effects* / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology; D014162:Transfection; D000097806:GluK2 Kainate Receptor
D004396:Coloring Agents; D018757:GABA Modulators; D018698:Glutamic Acid; D010424:Pentobarbital; D000644:Quaternary Ammonium Compounds; D018092:Kainic Acid Receptors; D000097806:GluK2 Kainate Receptor; C006798:brilliant green