Poly-A-rich domains in adrenal cell nuclear matrix after acute and chronicACTH stimulation: an in situ hybridization study

The regulatory effects of adrenocorticotropin (ACTH) at the adrenal cell nu cleus are not yet completely clarified. Recent studies showed that eukaryot ic cell nucleus is composed of specific subcompartments organized by the nu cleoskeleton-nuclear matrix. In this paper, the RNA polymerase II transcrip tional domains were detected in the adrenal nucleus after acute and chronic ACTH stimulation by using in situ hybridization. Polydeoxythymidine (poly- T) probe, complementary to the polyadenylated (poly-A) chain of all the mRN As and its precursors, was used. Hybridization was performed in intact adre nal cells and in nuclear matrices isolated from previously dispersed cells. The transcriptional domains, enriched in poly-A RNA, were evident in intac t adrenal cells, the staining intensity being higher both in the acutely an d in the chronically stimulated animals. In the nuclear matrices poly-A-ric h areas were still visible, and were more intensely stained after ACTH stim ulation.