We tested the effects of 17beta-estradiol as well as its catechol- and methoxy-derivatives, two androgens (DHEA and testosterone), a glucocorticoid (cortisol), a mineralocorticoid (aldosterone), and progesterone on the activity of ERK(1,2), a key component of the ERK/MAPK enzyme phosphorylation cascade, in SW-13 human adrenal carcinoma cells. After a 24-hour exposure SW-13 cells incubated with 10(-5) M concentrations of 17beta-estradiol, its 2-hydroxy or its 2-methoxy derivative, all had elevated ERK activities (196%, 159%, and 275%, respectively) relative to control cells (p < 0.01). Incubation with testosterone resulted in 162% of control ERK activity (p < 0.01), whereas incubation with the far weaker androgen DHEA or with cortisol, aldosterone, or progesterone had no significant effects. These findings suggest sex steroid-specific influences in the induction or activation of signal transduction pathways known to play a crucial role in cellular proliferation and differentiation.