These investigations are focussed on the molecular basis of the pathogenesis of heart and vascular diseases, with especially the changes occurring in the membrane structures and functions of the membrane-bound processes. The investigation is of interest in the changes in the interactions between the endothelial cells and the underlying cells and the activated cells in the circulation under pathological conditions as atherosclerosis, restenosis after PTCA, ischemia, heart failure, cardiomyopathies and cancer regress. Investigations of the effect of pharmaceuticals and nutrition are involved. These investigations are performed by studying the excitation-contraction coupling, stimulus-secretion coupling, mitochondrial functions, cell-cell interactions and interactions of the membranes with extracellular factors. Excitation-contraction is studied with heart and smooth muscle cells (heart failure, ischemia, hypertension), stimulus-secretion is studied with epithelial cells (pancreas, fibrosis, intestine), mitochondrial functions in heart and skeletal muscle mitochondria, and the cell-cell interactions between endothelial cells, monocytes, granulocytes and smooth muscle cells (atherosclerosis, photodynamic therapy).