Participation of GABAergic and histaminergic systems in inhibiting amygdaloid kindled seizures.
The effects of GABAmimetic drugs on inhibition of amygdaloid kindled seizures induced by clobenpropit were investigated to clarify the relationship between histaminergic and GABAergic systems in seizures. I.p. injection of clobenpropit caused dose-dependent inhibition of amygdaloid kindled seizures. GABAmimetic drugs such as diazepam, sodium valproate and muscimol also inhibited amygdaloid kindled seizures in a dose-dependent manner. Diazepam at doses of 0.2 and 0.5 mg/kg, which showed no significant effect on amygdaloid kindled seizures when used separately, significantly potentiated the effect of clobenpropit. Similar findings were observed with sodium valproate and muscimol at doses of 100 mg/kg and 5 ng, respectively, although neither showed any significant effects when administered separately. Bicuculline caused significant antagonism of the inhibition of amygdaloid kindled seizures induced by clobenpropit, while the effect of diazepam was not antagonized by diphenhydramine. These results suggested that inhibition of amygdaloid kindled seizures induced by histamine is closely associated with the actions of GABA.
Ishizawa
K
K
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Okayama University, Japan.
Chen
Z
Z
Okuma
C
C
Sugimoto
Y
Y
Fujii
Y
Y
Kamei
C
C
D000679:Amygdala / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D003975:Diazepam / Q000494:pharmacology; D006632:Histamine / Q000502:physiology*; D007093:Imidazoles / Q000494:pharmacology; D007696:Kindling, Neurologic / Q000187:drug effects*; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000517:prevention & control*; D013890:Thiourea / Q000031:analogs & derivatives / Q000494:pharmacology; D014635:Valproic Acid / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D007093:Imidazoles; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D014635:Valproic Acid; D006632:Histamine; D013890:Thiourea; D003975:Diazepam; C086108:clobenpropit; D001640:Bicuculline