[125I]iomazenil binding in the brains of spontaneously epileptic rats: an ex vivo quantitative autoradiographic study.
Central benzodiazepine receptor binding was studied in spontaneously epileptic rats (SER) and in their parent strain. Kyoto-Wistar (KW) rats, by ex vivo quantitative autoradiography with [125I]iomazenil. Thirteen-week-old SER developed tonic and absence-like seizures following mild stimulation by tapping at 5 min before injection of the radioligand. When compared with age-matched KW rats, a significant 76% elevation of radioactivity was observed in the SER hippocampus, while there was no difference in hippocampal blood flow obtained using [125I]N-isopropyl-p-iodoamphetamine. Since benzodiazepine receptors act to enhance inhibitory GABA transmission, this finding suggests a possible mechanism for seizure-induced enhancement of inhibition.
Nagata
T
T
Department of Radiology, Shiga University of Medical Sciences, Otsu, Japan.
Saji
H
H
Nishizawa
S
S
Yonekura
Y
Y
Yamamoto
I
I
Iida
Y
Y
Magata
Y
Y
Konishi
J
J
Serikawa
T
T
Yokoyama
A
A
D000818:Animals; D001345:Autoradiography / Q000379:methods; D001921:Brain / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D004827:Epilepsy / Q000378:metabolism*; D005442:Flumazenil / Q000031:analogs & derivatives* / Q000378:metabolism; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D009928:Organ Specificity; D051381:Rats; D011921:Rats, Inbred WKY; D011922:Rats, Mutant Strains; D011963:Receptors, GABA-A / Q000032:analysis / Q000378:metabolism*; D013045:Species Specificity; D013997:Time Factors
D007457:Iodine Radioisotopes; D011963:Receptors, GABA-A; D005442:Flumazenil; C063038:iomazenil