Bovine adrenal cells secrete interleukin-6 and tumor necrosis factor in vitro

Interleukin-6 (IL-6) and tumor necrosis factor (TNF) are secreted and/or sy nthesized by the rat and human adrenal cortex. In this study, the release o f IL-6 and TNF from bovine adrenal cells was determined. Bovine adrenal gla nds were collected from an abattoir and dissected into the zona glomerulosa (ZG), zona fasciculata (ZF), zona reticularis (ZR), and medulla. The tissu es were enzymatically dispersed to single cells and cultured for 4-6 days. The cells were then exposed (4 h) to angiotensin II(AII), adrenocorticotrop hic hormone (ACTH), phorbol dibutyrate (PDB), interleukin-1 beta (IL-I beta ), interleukin-1 alpha (IL-1 alpha), and endotoxin (LPS). The IL-6 and TNF content of the incubation medium was determined by bioassays. The release o f IL-6 and TNF from the ZG, ZF, ZR, and medulla was increased by PDB, IL-1 alpha, IL-1 beta, and LPS. In contrast, ACTH and AII increased IL-6 release from the ZG, ZF, and ZR but had no effect on IL-6 release from the medulla . ACTH decreased TNF release from all adrenal cortical zones but had no eff ect on TNF release from the medulla. Immunohistochemistry utilizing antibod ies against TNF alpha demonstrated TNF alpha-containing cells throughout th e adrenal gland. The majority of the cells of the ZG, ZF, and ZR contained TNF alpha. However, the cells of the ZG contained more TNF alpha than the c ells of the ZR or ZF. Small patches of TNF alpha-containing cells were also found in the adrenal medulla and capsule. These findings support the hypot hesis that IL-6 and TNF may have autocrine/paracrine effects on the adrenal gland. (C) 2000 Academic Press.