M. Fukinaga et al., ANTICONVULSANT PROPERTIES OF 1,4-BENZODIAZEPINE DERIVATIVES IN AMYGDALOID-KINDLED SEIZURES AND THEIR CHEMICAL STRUCTURE-RELATED ANTICONVULSANT ACTION, Pharmacology, 57(5), 1998, pp. 233-241
The effects of 14 different 1,4-benzodiazepines on amygdaloid-kindled
seizures and their chemical structure-related anticonvulsive actions w
ere studied. The prophylactic effects of 1,4-benzodiazepines on amygda
loid-kindled seizures were also examined. Male Wistar strain rats were
used in this study. Rats were anesthetized with pentobarbital sodium
(35 mg/kg i.p.) and bipolar electrodes were implanted into the right a
mygdala. The stimulating parameters were 1 ms pulse duration, 60 Hz fr
equency and a I s duration at an intensity just sufficient to induce a
fterdischarge (AD). All the 1,4-benzodiazepines depressed both seizure
stage and AD duration of amygdaloid-kindled seizures. Of the 1,4-benz
odiazepines, prazepam, flutoprazepam and flurazepam with a long alkyl
chain at position 1 were less effective than the drugs having a hydrog
en or methyl group at the same position. Nitrazepam, nimetazepam, flun
itrazepam and clonazepam which have a nitro group at position 7 showed
more potent antiepileptic activity than the drugs with a chloro group
. Certain 1,4-benzodiazepines caused inhibition of the development of
amygdaloid-kindled seizures. The existence of a hydrogen or methyl gro
up at position 1 and a nitro group at position 7 is important for exhi
biting potent anticonvulsant activity in amygdaloid-kindled seizures.
Introduction of an oxygen group at position 2 is also necessary for hi
gh activity. 1,4-benzodiazepines had not only therapeutic but also pro
phylactic effects on amygdaloid-kindled seizures.