Pentylenetetrazol-induced seizures increase [3H]L-2-amino-4-phosphonobutyrate binding in discrete regions of the rat brain.
Convulsions were induced in rats by a single injection of pentylenetetrazol (PTZ) and [3H]L-2-amino-4-phosphonobutyrate ([3H]L-AP4) in vitro receptor autoradiography was used to evaluate the effects on the expression of group III metabotropic glutamate receptors. Significant increases by 60-80% in [3H]L-AP4 binding was observed in the frontal parts of cortex (sensory, motor and cingulate cortex) and by 28% in the molecular layer of the cerebellar cortex 24 h after PTZ-induced seizures. Since group III metabotropic glutamate receptors has an inhibitory effect on glutamatergic transmission, the observed increases in binding may indicate that these receptors serve as a mechanism for preventing further seizure activity.
Thomsen
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Department of Molecular Pharmacology, Novo Nordisk A/S, Måløv, Denmark. cht@novo.dk
D000613:Aminobutyrates / Q000378:metabolism*; D000818:Animals; D000927:Anticonvulsants / Q000378:metabolism*; D001345:Autoradiography; D001921:Brain / Q000033:anatomy & histology; D001923:Brain Chemistry / Q000187:drug effects*; D003292:Convulsants; D005260:Female; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D010433:Pentylenetetrazole; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000378:metabolism*; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism*
C088229:2-amino-4-phosphonobutyrate receptor; D000613:Aminobutyrates; D000927:Anticonvulsants; D003292:Convulsants; D018094:Receptors, Metabotropic Glutamate; C012729:2-amino-4-phosphonobutyric acid; D010433:Pentylenetetrazole