the contractile system of smooth muscle exhibits distinctive responses to varying mg2+ concentrations in that maximum adenosine-5'-triphosphatase ( atpase ) activity of actomyosin requires relatively high concentrations of mg2+ and also that tension in skinned smooth muscle fibers can be induced in the absence of ca2+ by high mg2+ concentrations .
C1267092
smooth muscle
C1135918
smooth muscle fibers