ENHANCEMENT OF SECRETAGOGUE-INDUCED ADRENOCORTICOTROPIC HORMONE-RELEASE FROM CULTURED SHEEP ANTERIOR-PITUITARY-CELLS BY RECOMBINANT OVINE INTERLEUKIN-1
Rj. Kemppainen et En. Behrend, ENHANCEMENT OF SECRETAGOGUE-INDUCED ADRENOCORTICOTROPIC HORMONE-RELEASE FROM CULTURED SHEEP ANTERIOR-PITUITARY-CELLS BY RECOMBINANT OVINE INTERLEUKIN-1, American journal of veterinary research, 59(1), 1998, pp. 107-110
Objective-To determine whether recombinant ovine interleukin (oIL)-1 o
r oIL-2 alters basal or hypothalamic peptide-induced secretion of ACTH
from cultured sheep pituitary cells. Animals-The pituitary gland was
collected from castrated male sheep ranging from 0.5 to 1 year old. Pr
ocedure-Cells were cultured for 3 to 5 days, then were treated with oI
L for variable periods. Cells were washed and treated with the hypotha
lamic peptides corticotropin-releasing hormone (CRH) or arginine vasop
ressin (AVP) or both. Medium bathing the cells was collected and assay
ed for ACTH concentration. Results-Ovine IL-1 alpha and oIL-1 beta, bu
t not oIL-2, increased the amount of ACTH released in response to CRH,
AVP, and CRH and AVP combined. Both oIL were effective after 3, but n
ot 18 or 24 hours of exposure. Treatment with oIL-1 did not affect bas
al release of ACTH. Exposure of cells to phorbol 12-myristate 13-aceta
te or calphostin C before treatment with oIL-1 beta inhibited the abil
ity of the cytokine to augment ACTH release, suggesting a role for pro
tein kinase C in the process. Conclusions-Local concentration of oIL-1
in the sheep pituitary gland may have an important role in determinin
g secretion of ACTH in response to CRH or AVP or both from the hypotha
lamus. Clinical Relevance-The hypothalamic-pituitary-adrenocortical ax
is may be activated after immune challenge. The cytokine oIL-1 has bee
n implicated as an important mediator in this process. The pituitary g
land may be an important target for this effect.