Ultrastructural localization of the ROMK potassium channel in rat liver and heart

Abstract

The intracellular localization and distribution of the ROMK protein in rat liver and heart was studied by the electron microscopy of ultrathin sections using the antibodies against the ROMK channel protein, one of the contenders for the role of mitochondrial ATP-dependent potassium channel. In rat heart and liver tissues, the ROMK protein is localized on the membranes of mitochondrial cristae but differently distributed in hepatocytes and cardiomyocytes. In hepatocytes, colloidal gold particles were rather evenly distributed on the membranes of mitochondrial cristae. In cardiomyocytes, the number of granules was considerably lower than in hepatocytes, and they were also localized on the membranes of mitochondrial cristae and confined only by the center of these organelles.