Poly-A-rich domains in adrenal cell nuclear matrix after acute and chronic ACTH stimulation: an in situ hybridization...

The regulatory effects of adrenocorticotropin (ACTH) at the adrenal cell nucleus are not yet completely clarified. Recent studies showed that eukaryotic cell nucleus is composed of specific subcompartments organized by the nucleoskeleton-nuclear matrix. In this paper, the RNA polymerase II transcriptional 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 mRNAs and its precursors, was used. Hybridization was performed in intact adrenal cells and in nuclear matrices isolated from previously dispersed cells. The transcriptional domains, enriched in poly-A RNA, were evident in intact adrenal cells, the staining intensity being higher both in the acutely and in the chronically stimulated animals. In the nuclear matrices poly-A-rich areas were still visible, and were more intensely stained after ACTH stimulation.