TESTOSTERONE, DIHYDROTESTOSTERONE, TRENBOLONE ACETATE, AND ZERANOL ALTER THE SYNTHESIS OF CORTISOL IN BOVINE ADRENOCORTICAL-CELLS

The objective of this study was to examine the effect of anabolic ster oids (testosterone, T; dihydrotestosterone, D; trenbolone acetate, B; and zeranol, Z) on cortisol synthesis by cultured bovine adrenocortica l cells. Adrenal glands were obtained from slaughter-aged steers (n = 4). Cortical cells were isolated and their steroidogenic capacity was examined. They were plated in multiwell culture plates. At confluence, cells were treated with T, D, B, or Z at 0, 10, 50, 125, or 500 ng/mL (eight wells per treatment). Twenty-four hours after treatment, one-h alf of each treatment concentration was stimulated with 10(-9) M ACTH. After 8 h of incubation, cortisol concentration in the media was meas ured using RIA. Cortical cells were removed from the plates using 1 mM EDTA and analyzed for DNA content. Data were subjected to rank transf ormation and analyzed by randomized complete block design. Adrenocorti cotropic hormone stimulated (P < .01) the release of cortisol by more than threefold. Cortisol synthesis was lower (P < .05) in the presence of T, D, and B. Testosterone caused a greater (P < .05) suppression i n cortisol production at 50 and 125 ng/mL than did D. The suppression of cortisol synthesis did not differ between B and T or between B and D. Cortisol synthesis was lowered (P < .05) by the presence of T, D, a nd B in both ACTH-stimulated and nonstimulated cells but was only supp ressed in ACTH-stimulated cells of Z-treated cells. These data suggest that T, B, and D function to suppress the synthesis of cortisol in AC TH and nonstimulated cells, but that Z only reduces cortisol in ACTH-s timulated cells.