The effect of repeated physical exercise on hippocampus and brain cortex in stressed rats.
Sensitivity of target cells to glucocorticoids is regulated by the expression of intracellular glucocorticoid receptor (GR), which mediates the effects of glucocorticoids. The level of GR and of its nuclear transporter protein 70 (Hsp70) were followed in hippocampus and brain cortex of adult Wistar rat males exposed to acute (immobilization, cold) and chronic (social isolation, isolation, and 15 min daily swimming) stress or their combinations. Changes in plasma levels of adenocorticotropic hormone and corticosterone were also studied. A significant decrease in cytosol GR and Hsp70 was observed after acute stress. Opposite to that, chronic stress led to negligible changes in both cytosol GR and Hsp70 levels. Isolation, as chronic psychosocial stressor, caused reduced responsiveness to novel acute stressors, judged by the cytosol GR and Hsp70 levels. This was not observed if chronic isolation was combined with 15 min daily swimming prior to acute exposure to immobilization. The data suggest that repeated physical exercise may, at least in some cases, diminish detrimental effects of chronic social isolation on limbic-hypothalamic-pituitary-adrenocortical axis, as judged by the levels of GR and Hsp70 in the Wistar rat brain.
Filipović
Dragana
D
VINCA Institute of Nuclear Sciences Laboratory of Molecular Biology and Endocrinology, P.O. Box 522-090, 11001 Belgrade, Serbia and Montenegro. dragana@vin.bg.ac.yu
Gavrilović
Ljubica
L
Dronjak
Sladjana
S
Radojcić
Marija B
MB
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D002467:Cell Nucleus / Q000378:metabolism; D002540:Cerebral Cortex / Q000473:pathology*; D003345:Corticosterone / Q000097:blood; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006624:Hippocampus / Q000473:pathology*; D008297:Male; D010805:Physical Conditioning, Animal; D005082:Physical Exertion; D051381:Rats; D017208:Rats, Wistar; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D013312:Stress, Physiological
D018840:HSP70 Heat-Shock Proteins; D011965:Receptors, Glucocorticoid; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone