Angiotensin II (All)-binding sites in nuclei from rat liver: partial characterization of the mechanism of All accumulation in nuclei

Isoelectric focusing analysis showed a single angiotensin II (AII)-receptor complex migrating to pI 6.8 in nuclear preparations, while in plasma membranes a charge heterogeneity of the AII receptor subtype AT1 was observed. 125I-Labelled AII binding sites were found in intact nuclei and were not detected in nuclear extracts. Neither disruption of cytoskeletal elements by colchicine nor prevention of endosome acidification by chloroquine had any effect on nuclear accumulation of AII. Nevertheless, the monovalent ionophore monensin inhibited nuclear accumulation of 125I-labelled AII. Our findings are consistent with the hypothesis that processing through the Golgi apparatus could be involved in the nuclear accumulation of AII.