125I-iomazenil-benzodiazepine receptor binding during psychological stress in rats.
OBJECTIVE
We investigated the changes in 125I-iomazenil (125I-IMZ) benzodiazepine receptor (BZR) binding with psychological stress in a rat model.


METHODS
Six male Wistar rats were placed under psychological stress for 1 hour by using a communication box. No physical stress was not received. 1.85 MBq of 125I-IMZ was injected into the lateral tail vein and the rat was killed 3 hours later. Twenty-micrometer-thick sections of the brain were collected and % injected dose per body weight (%ID/BW) of eleven regions (frontal, parietal, temporal, occipital cortices, caudate putamen, accumubens nuclei, globus pallidus, amygdala, thalamus, hippocampus and hypothalamus) were calculated by autoradiography. The %ID/BW of rats which were placed under psychological stress was compared with that of 6 control rats.


RESULTS
The %ID/BW of rats which were placed under psychological stress diffusely tended to show a reduction in 125I-IMZ-BZR binding. A significant decrease in BZR binding was observed in the hippocampus of the rats which were placed under psychological stress.


CONCLUSIONS
125I-IMZ-BZR binding tended to decrease throughout the brain.
Fukumitsu
Nobuyoshi
N
Department of Radiology, Jikei University School of Medicine, Tokyo, Japan. GZL13162@nifty.ne.jp
Tsuchida
Daisuke
D
Ogi
Shigeyuki
S
Uchiyama
Mayuki
M
Mori
Yutaka
Y
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D004597:Electroshock / Q000009:adverse effects*; D005442:Flumazenil / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D008297:Male; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000378:metabolism*; D012016:Reference Values; D013315:Stress, Psychological / Q000000981:diagnostic imaging / Q000209:etiology* / Q000378:metabolism*
D019275:Radiopharmaceuticals; D011963:Receptors, GABA-A; D005442:Flumazenil; C063038:iomazenil