125I-iomazenil - benzodiazepine receptor binding and serum corticosterone level during psychological stress in a rat model.
To test the hypothesis that benzodiazepine receptor density decreases in response to stress, we correlated (125)I-iomazenil ((125)I-IMZ) binding with serum corticosterone levels in a rat model. Wistar male rats were divided into four groups; control group (CON, 10 rats), no physical or psychological stress; and one-, three-, and five-day stress groups of 12 rats each (1-DAY, 3-DAY, and 5-DAY, respectively), receiving psychological stress for the given number of days. Psychological stress were given to rats with a communication box. The standardized uptake value (SUV) of (125)I-iomazenil of the 3-DAY and 5-DAY showed that (125)I-iomazenil-benzodiazepine receptor binding was significantly reduced in the cortices, accumbens nuclei, amygdala and caudate putamen (p<0.05). Serum corticosterone level ratio appeared to be slightly elevated in 3-DAY and 5-DAY, although this elevation was not significant. These data suggest that (125)I-IMZ is a useful radioligand to reflect received stress and its binding in the cortices, accumbens nuclei, amygdala and caudate putamen is strongly affected by psychological stress.
Fukumitsu
Nobuyoshi
N
Department of Radiology, Jikei University School of Medicine, Tokyo, Japan. GZL13162@nifty.ne.jp
Ogi
Shigeyuki
S
Uchiyama
Mayuki
M
Mori
Yutaka
Y
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D003345:Corticosterone / Q000097:blood*; D005442:Flumazenil / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D008297:Male; D011485:Protein Binding; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000378:metabolism*; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013315:Stress, Psychological / Q000097:blood* / Q000000981:diagnostic imaging / Q000378:metabolism*; D014018:Tissue Distribution
D019275:Radiopharmaceuticals; D011963:Receptors, GABA-A; D005442:Flumazenil; C063038:iomazenil; D003345:Corticosterone