[The antiepileptic effects of the combined action of the new 1,4-dihydropyridine derivative glutapyrone with sodium valproate and phenobarbital]. / Antiépilepticheskie éffekty sochetannogo vozdeistviia novogo proizvodnogo 1,4-digidropirina glutapirona s val'proatom natriia i fenobarbitalom.

Antiepileptic effects of a novel amino acid-containing 1,4-dihydropyridine glutapyrone and sodium valproate during combined therapy on generalized pentylenetetrazol- and focal 4-aminopyridine-induced epileptic activity in rat brain cortex were studied, as were combined effects of glutapyrone and phenobarbital on maximal electroshock in mice. The results of these investigations suggest that combined treatment by glutapyrone and sodium valproate or phenobarbital is reasonable and helps potentiate the effect of each drug, thus significantly reducing their doses, and minimize the risk of side effects of the drugs id used in higher doses in case of long treatment.

[The anticonvulsant properties of glutapyrone--a new type of derivative of amino acid-containing 1,4-dihydropyridines]. / Protivosudorozhnye svoistva glutapirona--proizvodnogo novogo tipa--aminokislot-soderzhashchikh 1,4-digidropiridinov.

Experiments on male Wistar rats and Icr:Icl mice studied the influence of the novel compound--amino acid-containing 1,4-dihydropyridine derivative glutapyrone (G) on acute generalized seizures, arecoline and nicotine tremor, and 45Ca2+ uptake in brain synaptosomes. It was shown that G produced significant antiepileptic effects on models of acute pentylenetetrazole seizures on rats and mice. Efficiency of antiepileptic effect depended on a dose and method of modeling seizures: it was more effective in case of intravenously pentylenetetrazole-induced seizure tested by clonic and tonic seizure components and death. The results suggest the participation of GABAergic system in realization of antiepileptic effect of G. Glutapyrone did not influence the 45Ca2+ uptake by rat cortical synaptosomes (evoked by a 1-min depdariration with 55 mM K+), this suggests that G lacked calcium antagonist properties characteristic of 1,4-dihydropyridine compounds such as nifedipine, nimodipine. In addition, G does not affect N- and M-cholinergic processes.

[Anti-epileptic effect of the new calcium channel blocker IOS-1.1212]. / Antiépilepticheskie éffekty novogo blokatora Ca-kanalov IOS-1.1212.

In experiments on freely moving male Wistar rats it was shown that IOS-1.1212 (1,4-dihydropyridine) in a dose 2 and 10 mg/kg (i. p.) suppressed the penicillin-induced focal epileptic activity in cerebral cortex. Similar suppressing effect of IOS-1.1212 was shown on acute generalized tonic-clonic pentylenetetrazol (PTZ) seizures (75 mg/kg i. p.) and on chronic PTZ administration (PTZ-kindling, 30 mg/kg i. p. during 30 days): when injected 30 min before each PTZ administration it delayed the development of kindling-induced seizures susceptibility in randomized animals (series 1) and attenuated the severity of seizures in PTZ-sensitive animals (series 2). However, IOS-1.1212 had no effect on the strychnine-induced focal epileptic activity. In male Icr:Icl mice IOS-1.1212 in a dose 1.5 and 5 mg/kg also influenced the PTZ convulsions (i. v. titration of 1% solution at a rate of 0.01 ml/s) and had no effect on the strychnine convulsions (i. v. titration of 0.01% solution at a rate of 0.01 ml/s) and on maximal electroshock. In addition, IOS-1.1212 significantly increased antiepileptic effect of phenobarbital on maximal electroshock.

[Effect of a Ca-channel blocker, ryodipine, on focal and generalized epileptic activity]. / Vliianie blokatora Ca-kanalov riodipina na ochagovuiu i generalizovannuiu épilepticheskuiu aktivnost'.

The experiments were performed on 102 freely moving Wistar rats. Epileptic foci were produced by the application of a filter paper soaked in a sodium benzylpenicillin solution (20,000 IU/ml) onto sensorimotor cortex. It was shown that an intraperitoneal administration of ryodipine (1,2 and 5 mg/kg) during a steady epileptic activity (EA) resulted in suppression of EA in most animals. Antiepileptic effect of ryodipine was manifested by a decreased frequency and amplitude of interictal discharges and a less frequent appearance of ictal discharges (ID). Prior administration of ryodipine (2 mg/kg) 30 min before producing the focus of EA resulted in an increased latency and decreased number of ID, and shortening of the duration of the focus of EA. Generalized convulsions were induced by intraperitoneal of pentylenetetrazol (60 mg/kg). Ryodipine (2 mg/kg, 30 min before pentylenetetrazol) increased latency to first convulsive episodes and delayed the development of generalized tonic-clonic seizures.

Pharmacological and toxicological properties of ryodipine.

2,6-Dimethyl-3,5-dimethoxycarbonyl-4-(o-difluoromethoxy-p hen yl)-1,4-dihydropyridine (ryodipine, PP-1466) causes lasting decrease in systolic and diastolic arterial pressure at intravenous and oral administration to anesthetized animals. In conscious rats with DOCA-salt (des-oxycortone) and spontaneous hypertension, as well as in rats with hypertension provoked by method of cellophane perinephritis, PP-1466 (1 and 10 mg/kg, orally) decreases systolic pressure considerably. Therapeutic doses of PP-1466 do not essentially affect rhythm and frequency of cardiac contractions. High doses of the drug increase the heart rate. PP-1466 increases coronary blood flow. PP-1466 antagonizes considerably the pressor effect of angiotensin. In this respect PP-1466 is superior to SKF-24260 (2,6-dimethyl-3,5-diethoxycarbonyl-4-(o-difluoromethylphenyl)-1, 4-dihydropyridine). PP-1466 reduces hypotensive reaction and tachycardia induced by isoprenaline administration, inhibits decrease in arterial pressure caused by electric stimulation of the vagus nerve and administration of acetylcholine. Hypotension caused by PP-1466 and its negative inotropic effect can be antagonized with calcium chloride. In mice and rats PP-1466 at doses exceeding 10 mg/kg exerts a certain dose dependent depressant effect on the CNS. More protracted depressant effect on the CNS is exerted by nifedipine which was studied parallelly. In rabbits oral PP-1466 decreases in EEG basic rhythm amplitude both in cortical and subcortical structures. High doses of the drug lead to dysrhythmia in bioelectric activity. Acute, subacute and chronic toxicity studies in mice, rats and dogs show that PP-1466 possesses low acute toxicity and is well tolerated at protracted repeated administration of therapeutic and several times higher doses.

[Demethylation of methindione]. / Demetilirovanie metindiona.

Methindion demethylation was shown to occur in rats. This process proceeds with the participation of NADPH-dependent transport system of microsomal electrons. In experiments in vivo methindion demethylation coursed at a high rate and was accompanied by a partial loss of its anticonvulsive effects.