Effects of corticosterone in vivo and in vitro on adrenocorticotropic hormone production by corticotropin releasing factor-stimulated leukocytes.

Corticotropin releasing factor (CRF) and corticosterone have been shown to affect immune cell function. Previously, we have shown that CRF stimulates immunoreactive adrenocorticotropic hormone (ACTH) production by leukocytes. In this study, splenic leukocytes from corticosterone-injected chickens failed to show a CRF-induced increase in ACTH production. In addition, corticosterone in vitro inhibited the production of leukocyte ACTH as well as the stimulatory effect of CRF on splenic leukocyte ACTH production. These findings show that, as with anterior pituitary ACTH production, CRF-stimulated leukocyte ACTH production is inhibited by glucocorticoids.