Morphological examination of cardiac glycoside in myocardial cells

The present study primarily focuses on the analysis of digoxin binding of the heart muscle cells. The primary aim of the investigation was to demonstrate cardiac glycoside morphologically. In immunohistochemistry the development of recent years has been provided by the application of monoclonal antibodies and their Fab fragments by the application of monoclonal antibodies as reagents. The direct immunofluorescence method with digoxin specific monoclonal antibody or Fab fragments and FITC or peroxidase conjugated antisera are useful for morphological examination of digoxin binding and localization in cardiac muscle cells. The newly developed immunofluorescence and electron microscopic methods for determination morphologically of digoxin binding on the cell membrane were evaluated with regard to reproducibility, accuracy and specificity of drug binding. With immunofluorescence and electronmicroscopic methods, linkage can be observed on the sarcolemma membrane and on the cell wall of capillary and arterioles in myocardial cells treated by cardiac glycoside. The specificity of reaction is provided by the negative reaction of cells, not treated by digoxin. Intensity of reaction depends on the concentration. It shows the sensitivity of method that cardiac glycoside linked to the cell membrane can be detected in the upper sphere of therapeutic dose. Application of immunofluorescence method is manifold and relatively simple and quick method which can be used in diagnostics. The electronmicroscopic peroxidase method is a useful method to study of localization of cardiac glycoside receptors of cell membrane.