抄録
ATP-dependent relaxing factor of glycerinated muscle fibres isolated from skeletal muscle consists of two components, the one is contained in 10-20 g/dl fraction of ammonium sulfate and the other in 30-40 g/dl. Each one of them, fractionated twice by ammonium sulphate, has little, if any, activities by itself. The collaboration of these two components, however, give rise to strong relaxation comparable to that by the original factor.
