I-125-iomazenil-benzodiazepine receptor binding and serum corticosterone level during psychological stress in a rat model

摘要

To test the hypothesis that benzodiazepine receptor density decreases in response to stress, we correlated I-125-iomazenil (I-125-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 I-125-iomazenil of the 3-DAY and 5-DAY showed that I-125-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 I-125-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. (C) 2004 Elsevier Inc. All rights reserved.