Electron Microscopic Study on Distribution of Sodium and Potassium Ion in Cardiac Ventricle Muscle Cells Influenced by Ouabain

Sodium dihydroxytartrate osazone added to the fixative solution was used for the subcellular localization of calcium ion in the tissue in situ. In the mouse cardiac muscle, the resulting precipitate distributed inside the terminal cisternae and in a lesser amount inside and around the longitudinal tubule of the sarcoplasmic reticulum. There were also occasional deposits in the myofibrils, especially over the Z line.