gamma-glutamyltransferase ( ( 5-glutamyl ) -peptide : amino-acid 5-glutamyltransferase , ec 2.3.2.2 ) activity of wi-38 fibroblasts decreased only slightly in relation to a constant amount of cell-associated protein as the cells were carried in culture serially from middle to late passage numbers leading toward senescence , e.g. , from population doubling level 27 through 41 .
C0016030
fibroblasts
C0007634
cells