in studies on the mechanism ( s ) of these actions , we have measured the activities of ornithine decarboxylase ( odc ) , an enzyme associated with rapid cell proliferation , and creatine kinase ( ck ) , a biochemical marker for muscle differentiation , after treatment of l6 myoblast cultures with multiplication stimulating activity ( msa ) , a member of the somatomedin family of insulinlike growth factors .
C0021666
multiplication stimulating activity
C0037657
insulinlike growth factors