Restraint stress-induced elevations in plasma corticosterone and beta-endorphin are not accompanied by alterations in immune function.
A variety of stressors activate the hypothalamic-pituitary-adrenal (HPA) axis, thereby resulting in elevated levels of circulating ACTH, beta-endorphin and corticosterone. Since these hormones have been shown previously to alter measures of immune function, we determined whether presentation of a stressor which activates the HPA axis produces a concomitant alteration in immune function. Restraint stress resulted in significantly elevated levels of corticosterone and beta-endorphin without affecting either proliferative or cytolytic activities of lymphocytes. At concentrations similar to those achieved during stress, in vivo, corticosterone exhibited a dose- and time-dependent reduction in both lymphocyte proliferation as well as natural killer cytotoxicity, in vitro. beta-Endorphin, on the other hand, was without direct or modulatory effects. These results indicate that restraint stress-induced activation of the HPA axis occurs without accompanying alterations in immune function.
Flores
C M
CM
Department of Pharmacology, Georgetown University Medical Center, Washington, DC 20007.
Hernandez
M C
MC
Hargreaves
K M
KM
Bayer
B M
BM
D000818:Animals; D003345:Corticosterone / Q000097:blood* / Q000494:pharmacology; D007030:Hypothalamo-Hypophyseal System; D007694:Killer Cells, Natural / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D010913:Pituitary-Adrenal System; D051381:Rats; D011919:Rats, Inbred Strains; D012149:Restraint, Physical; D013312:Stress, Physiological / Q000097:blood / Q000276:immunology*; D001615:beta-Endorphin / Q000097:blood* / Q000494:pharmacology
D001615:beta-Endorphin; D003345:Corticosterone