Visit our Expo - Redox and Inflammation signaling 2012

Session XIV : Transcriptional and translational control Poster XIV, 20
Daily swimming diminishes the isolation-induced changes on the level of glucocorticoid
receptor and heat shock protein 70 in rat brain
Filipovi' M. Dragana, Gavrilovi' Ljubica, Dronjak Sladjana and Radoj(i' B. Marija
Institute of Nuclear Sciences «Vin(a», Laboratory of Molecular Biology and
Endocrinology,11000 Belgrade, Serbia and Montenegro. E-mail : dragana@vin.bg.ac.yu
Animals chronically exposed to a particular stressor display an exaggerated response of
hypothalamo-pituitary adrenal axis to various novel stressors, as judged by plasma level of
glucocorticoids and adrenocorticotropic hormone (ACTH). The molecular mechanism of such
observation is believed to involve the action of glucocorticoid receptor (GR) and its nuclear
transporter heat shock protein 70 (Hsp70). The main aim of the present study was to define
the change on the level of GR and Hsp70 in a cytosol of hippocampus and brain cortex of
Wistar rat males exposed to 21 daily isolation or isolation plus 15 minute/daily swimming as
chronic stressors, sole or in combination with 2h acute stress of immobilization or cold (40C).
The level of GR and Hsp70 were quantified by Western immunoblotting. Plasma ACTH and
corticosterone (CORT) were measured by chemiluminescent method and RIA, respectively. A
significant decrease of both proteins was observed in acutely stressed rats. Chronic stress
conditions led to moderate decreases in both cytosol GR and Hsp70 level. Isolation as chronic
stressor caused reduced responsiveness to a novel acute stressors, judged by the cytosol GR
and Hsp70. This was not observed when isolation plus swimming preceeded the application
of the acute stressors. The only exeption was GR level when isolation plus swimming were
followed by immobilization. The obtained results led to the conclusion that 15 minute/daily
swimming may diminish chronic social isolation-induced changes on the levels of
glucocorticoid receptor and heat shock protein Hsp70 in cytosol of hippocampus and brain
cortex of rats.
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