Area-dependent CNS membrane response of muscarinic receptor to convulsant 3-mercaptopropionic acid.
It has already been shown that the administration of convulsant 3-mercaptopropionic acid at 150 mg/kg enhances binding affinity of muscarinic antagonist [3H]quinuclidinyl benzilate ([3H]QNB) to certain rat CNS membranes without affecting site number. Herein we employed a 100 mg/kg dose and tested [3H]QNB binding to cerebellar, hippocampal, and striatal membranes obtained from rats killed at preseizure, seizure, and postseizure stages. In cerebellum, binding increased 24, 65, and 19% a1 preseizure, seizure, and postseizure stages, respectively; in hippocampus, values were 12 and 20% higher at pre- and seizure stages, but failed to differ from controls at postseizure; in striatum, increases of 10 and 18% were recorded at seizure and postseizure, with no changes at preseizure. Neither a subconvulsant dose (20 mg/kg) nor in vitro drug addition had any effect on binding. Results indicate a differential response to the convulsant, with reversible changes in cerebellum and hippocampus, and a delayed response in striatum, supporting the concept of area-dependent neuronal plasticity.
Schneider
P G
PG
Instituto de Biología Celular y Neurociencias, Facultad de Medicina, Universidad de Buenos Aires, Paraguay, Argentina.
Rodríguez de Lores Arnaiz
G
G
D015097:3-Mercaptopropionic Acid / Q000494:pharmacology*; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D002531:Cerebellum / Q000187:drug effects / Q000378:metabolism; D003292:Convulsants / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008566:Membranes / Q000187:drug effects; D018727:Muscarinic Antagonists / Q000378:metabolism; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000187:drug effects*; D012640:Seizures / Q000139:chemically induced / Q000503:physiopathology
D003292:Convulsants; D018727:Muscarinic Antagonists; D011976:Receptors, Muscarinic; D011813:Quinuclidinyl Benzilate; D015097:3-Mercaptopropionic Acid