[Effects of corazol on the regulation of GABAa receptor-channel complex].
Effects of corazol (pentylenetetrazole, PTZ) on the GABAA receptor-channel complex mediated 36Cl- influx into synaptoneurosomes isolated from rat cerebral cortex, were studied. PTZ inhibited the 36Cl- influx stimulated by a GABA agonist, muscimol, concentration-dependently with an IC50 of 2.11 +/- 0.25 mM. In addition, the rate of muscimol-dependent desensitization of the GABAA receptor-channel complex was significantly reduced in the presence of PTZ. Apparently, the superimposition of these two mutually opposing effects is the cause of a mixed (competitive/noncompetitive) type of inhibition displayed by PTZ. The rate of desensitization of GABAA receptor-channel complex is suggested to be regulated by intracellular concentration of Cl- through a feed-back mechanism.
Kryzhanovskiĭ
G N
GN
Rebrov
I G
IG
Glebov
R N
RN
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D005246:Feedback; D066298:In Vitro Techniques; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D010433:Pentylenetetrazole / Q000494:pharmacology*; D051381:Rats; D011963:Receptors, GABA-A / Q000378:metabolism*; D013268:Stimulation, Chemical
C062606:GABA-benzodiazepine receptor-chloride ionophore complex; D011963:Receptors, GABA-A; D009118:Muscimol; D010433:Pentylenetetrazole
Deĭstvie korazola na reguliatsiiu GAMKa-kanal-retseptornogo kompleksa.