Immobilization stress-induced thymocyte apoptosis in rats.
Immobilization of rats is a well known model of emotional stress. We studied apoptosis in rat thymocytes during immobilization for 2-8 hours (h). Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells increased with time of immobilization. The positive cells increased significantly after 2 h and comprised about 33% of total cells after 8 h. The apoptotic cells aggregated as scattered foci predominantly in the cortex of the thymus and diffusely distributed with time of the stress. The DNA laddering also increased with time of immobilization, which was inhibited by a glucocorticoid receptor antagonist, RU-486. These results suggest that the emotional stress evoked by immobilization induces thymocyte apoptosis through glucocorticoid overflow.
Hatanaka
K
K
Department of Forensic Medicine, Graduate School of Medicine, University of Tokyo, Japan. hatanaka@m.u-tokyo.ac.jp
Ikegaya
H
H
Takase
I
I
Kobayashi
M
M
Iwase
H
H
Yoshida
K
K
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002352:Carrier Proteins / Q000378:metabolism; D053938:DNA Fragmentation; D006727:Hormone Antagonists / Q000494:pharmacology; D007103:Immobilization / Q000502:physiology*; D020287:In Situ Nick-End Labeling; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism; D015735:Mifepristone / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological / Q000503:physiopathology*; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D013049:Spectrin
D002352:Carrier Proteins; D006727:Hormone Antagonists; D008840:Microfilament Proteins; D015735:Mifepristone; D011493:Protein Kinase C; D013049:Spectrin