[Comparative evaluation of anticonvulsant and anti-arrhythmic effects of phenazepam, a benzodiazepine receptor agonist]. / Sravnitel'naia otsenka protivosudorozhnogo i antiaritmicheskogo éffektov agonista benzodiazepinovykh retseptorov fenazepama.

It was established on white mice that benzodiazepine receptor agonist phenazepam possessed a high anticonvulsant activity to antagonize bicuculline, corrasol, picrotoxin and thiosemicarbazide. It was also shown that phenazepam had a potent antiarrhythmic effect on ischemic and reperfusion cardiac arrhythmias in Wistar rats in situ. The effect was of a central nature since it was irreproducible in isolated heart. It seems to be due to the potentiating effect of phenazepam on the realization of GABA inhibitory control of centers of the heart regulation. The facts obtained evidence a possibility of using phenazepam not only as an anticonvulsant but also as an antiarrhythmic means.

Antiseizure activity of gamma-acetylenic gamma-aminobutyric acid: a catalytic irreversible inhibitor of gamma-aminobutyric acid transaminase.

gamma-Acetylenic gamma-aminobutyric acid (gamma-acetylenic GABA) produces several-fold sustained elevations of brain GABA concentrations when administered intraperitoneally to mice. It protects mice against seizures induced by audiogenic stimuli, electroshock, thiosemicarbazide, isoniazid and strychnine. The duration and degree of audiogenic seizure protection appears to correlate with elevations in whole brain GABA levels. gamma-Acetylenic GABA does not protect against seizures induced by pentylenetetrazol or picrotoxin even at doses that increase brain GABA concentrations approximately 6-fold. This differential antiseizure activity suggests that the GABA system may play a role in some, but not all experimentally produced seizures.

[The mechanism of the anticonvulsive action of diazepam]. / K mekhanizmu protivosudorozhnogo deistviia diazepama

Diazepam was shown to be highly efficient in preventing the convulsive siezures induced by thiosemicarbazide and connected with GABA insufficiency. In recording the recovery cycles of the intracortical response of the cat motor cortex it was found that diazepam induced a decrease of the testing respone. These data indicate the enhancement of the inhibitory processes. Using this test an antagonistic relationship was observed between diazepam on the one hand, and biculline and thiosemicarbazide--on the other Diazepam was capable of increasing GABA content in the brain by suppressing GABA-transaminase activity in the mitochondrial fraction of the brain tissue.