[Interaction of piracetam with 3H-imipramine binding sites and the GAMA-benzodiazepine receptor complex of brain membranes].
Piracetam at a concentration of 10(-6) M was shown to behave as a noncompetitive inhibitor of 3H-imipramine specific binding to rat brain membranes. At the same time piracetam failed to influence specific binding of 3H-mianserin to membranes of guinea-pig cerebellum, which is indicative of its inability to suppress histamine H1 receptors, a component of 3H-imipramine specific binding sites. At a concentration of 10(-4) M piracetam does not change specific binding of 3H-flunitrazepam to rat hippocampal membranes in the absence of GABA, but in the presence of 5 X 10(-5) M GABA, like atypical tranquilizer mebicar, acts as a competitor of 3H-flunitrasepam binding. Though Ro-15 1788 did not suppress anxyolytic piracetam (and mebicar) effect, our results give evidence of a possible involvement of GABA-benzodiazepine supramolecular complex in the anxiolytic activity of piracetam.
D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D002352:Carrier Proteins; D002531:Cerebellum / Q000378:metabolism; D006168:Guinea Pigs; D006624:Hippocampus / Q000378:metabolism; D007099:Imipramine / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D008566:Membranes / Q000378:metabolism; D010889:Piracetam / Q000378:metabolism* / Q000494:pharmacology; D011760:Pyrrolidinones / Q000378:metabolism*; D051381:Rats; D011955:Receptors, Drug; D011963:Receptors, GABA-A / Q000378:metabolism*; D017981:Receptors, Neurotransmitter / Q000378:metabolism*
D002352:Carrier Proteins; D011760:Pyrrolidinones; D011955:Receptors, Drug; D011963:Receptors, GABA-A; D017981:Receptors, Neurotransmitter; C027775:imipramine receptor; D007099:Imipramine; D010889:Piracetam
Vzaimodeĭstvie piratsetama s mestami spetsificheskogo sviazyvaniia 3H-imipramina i GAMK-benzodiazepinovym retseptornym kompleksom membran golovnogo mozga.