[Distribution of 5'-nucleotidase in fractions of rat yolk-sac after differential centrifugation and isopycnic sucrose gradient centrifugation].

The 5'-nucleotidase considered as a marker enzyme of the plasma membranes shows a highly specific acitvity in both nuclear and mitochondrial-lysosomal fractions of the rat yolk-sac. In isopycnic sucrose gradient fractionation of the mitchondrial-lysosomal fraction a relative accumulation of this enzyme could be shown in the density level of the phagolysosomes (d = 1,16--1,20).