Glucocorticoids Potentiate the Prostaglandin E1-Mediated Cyclic AMP Formation by a Cultured Murine Neuroblastoma Clone

Abstract

The effect of steroid hormones on the prostaglandin E₁ (PGE₁)‐mediated cyclic AMP formation by murine neuroblastoma clone N1E‐115 was studied. Dexamethasone at submicromolar concentrations and corticosterone at micromolar concentrations (steroids with glucocorticoid activity) were able to modify the PGE₁‐mediated response whereas testosterone, progesterone, and estradiol each at 10 μM had no effect. Glucocorticoids added to the culture medium of N1E‐115 cells produced an increase in the maximal response to PGE₁ only after long‐term (4 h) incubation with the hormone. Inhibitors of protein and RNA synthesis blocked this effect of glucocorticoids. Basal activity of adenylate cyclase in treated cells was twofold higher than that in control cells, and this enzyme seemed to be the primary target for the hormone action, since the activity of 3′:5′‐cyclic AMP phosphodiesterase and the binding of [³H]PGE₁ to its receptors were not altered by glucocorticoid treatment. Our results indicate that glucocorticoids modulate receptor‐mediated responses in cells of neural origin through a mechanism that involves induction of protein synthesis.