|Carroll, Jeffery - Jeff Carroll|
Submitted to: Meeting Abstract
Publication Type: Experiment Station
Publication Acceptance Date: 6/10/1998
Publication Date: N/A
Technical Abstract: This study assessed the direct actions of IL-1beta (IL-1b), IL-6 and TNFalpha (TNF) on adrenal steroidogenesis and determined whether mRNAs for these cytokines were expressed in the bovine adrenal gland. Primary cultures of adrenocortical cells were treated with recombinant human IL-1b, IL-6 or porcine TNF with or without ACTH, and cortisol content in 4-hr culture supernatants was determined by RIA. Each of the tested cytokines at doses >.1 ng/ml reduced ACTH-stimulated cortisol production (P<.05). The presence of intra-adrenal mRNA for IL-1b, IL-6 and TNF was determined in adrenal glands obtained at slaughter from 19 steers that represented a spectrum of adrenal gland weights (13 to 24g). Bovine peripheral blood mononuclear cells (PBMC) were used as positive controls for expression of cytokine mRNA. RT-PCR on PBMC generated bands of 795, 522 and 683 bp for IL-1b, IL-6 and TNF, respectively. A product of -795 bp was reproducibly amplified from adrenocortical RNA in 16 of 19 steers when IL-1b specific primers were used; a -520 bp product was detectable in 11 of the steers using IL-6 specific primers; and a -680 bp product was seen in 13 of 19 steers when TNF specific primers were used. RNA for all three cytokines was detectable in adrenocortical samples from 10 of the 19 steers, and no steer was negative for all three cytokines. Steers that had detectable mRNA for all three cytokines in adrenocortical tissue had intermediate adrenal gland weights, and those that were negative for 1 or 2 cytokines generally had adrenal gland weights in the lower (<16 g) or higher (>22 g) ends of the sample population. The data suggest that expression of IL-1b, IL-6 and TNF genes (or related genes) occurs in the bovine adrenal gland and that adrenal steroidogenesis may be affected by these cytokines.