Distribution of Ca in different regions of heart muscle cell

Electron microscopic autoradiographic investigations to study the localization of Ca in muscle were performed using heart muscle. The distribution of autoradiographic grains, originating from 45Ca were compared above myofibrils and interfibrillar spaces of the ventricle, auricle and sinus node of the heart. The aim was to get new data on the role of Ca in the mechanical activity of muscle with special consideration of the Ca content of interfibrillar spaces. The different distribution of grains in the muscle fibrils and interfibrillar spaces of various parts of the heart can be in connectrion with the different activities of these parts. (author) 23 refs