IBCN   20355
INSTITUTO DE BIOLOGIA CELULAR Y NEUROCIENCIA "PROFESOR EDUARDO DE ROBERTIS"
Unidad Ejecutora - UE
artículos
Título:
Ketamine prevents seizures and reverses changes in muscarinic receptor induced by bicuculline in rats.
Autor/es:
P. G. SCHNEIDER ; G. RODRÍGUEZ DE LORES ARNAIZ
Revista:
NEUROCHEMISTRY INTERNATIONAL
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Año: 2013 vol. 62 p. 258 - 264
ISSN:
0197-0186
Resumen:
The cholinergic system has been implicated in several experimental epilepsy models. In a previous study
bicuculline (BIC), known to antagonize GABA-A postsynaptic receptor subtype, was administered to rats
at subconvulsant (1 mg/kg) and convulsant (7.5 mg/kg) doses and quinuclidinyl benzilate ([3H]-QNB)
binding to CNS membranes was determined. It was observed that ligand binding to cerebellum increases
while it decreases in the case of hippocampus. Saturation binding curves showed that changes were due
to the modification of receptor affinity for the ligand without alteration of binding site number. The purpose
of this study was to assay muscarinic receptors employing other BIC dose (5 mg/kg), which induces
seizures and allows the analysis of a postseizure stage as well. To study further muscarinic receptor
involvement in BIC induced seizures, KET was also employed since it is a well known anticonvulsant
in some experimental models. The administration of BIC at 5 mg/kg to rats produced a similar pattern
of changes in [3H]-QNB binding to those recorded with 1.0 and 7.5 mg/kg doses. Here again, changes were
observed in receptor binding affinity without alteration in binding site number for cerebellum or hippocampus
membranes. Pretreatment with KET (40 mg/kg) prevented BIC seizures and reverted [3H]-QNB
binding changes induced by BIC administration. The single administration of KET invariably resulted in
[3H]-QNB binding decrease to either cerebellar or hippocampal membranes. KET added in vitro decreased
ligand binding likewise. Results of combined treatment with KET plus BIC are hardly attributable to the
single reversion of BIC effect since KET alone invariably decreased ligand binding. It is suggested that
besides alteration of cholinergic muscarinic receptor other(s) neurotransmitter system(s) may well also
be involved.