In vitro effects of ACTH on uridine incorporation into rapidly labelled adrenal RNA of normal and dexamethasone-suppressed rats

Adrenals from control and dexamethasone suppressed rats were incubated in a continuous flow system and exposed to ACTH and radioactive uridine. The adrenal response to ACTH was measured by corticosterone determination in the effluent medium. Cytoplasmic RNA was extracted and fractionated by polyacrylamide gel electrophoresis. ACTH increased the incorporation of labelled uridine into total RNA and all RNA species on the gels of normal and suppressed adrenals, but with a preferential incorporation into the 18S fraction.