the ultrastructural study of non-decalcified periodontal ligament of rats , labeled with horseradish peroxidase used as an enzymatic tracer for the mechanism of endocytosis , shows that there exists in the fibroblast , on the one hand , an endogeneous peroxidase revealed by the preparation and characteristic of certain cellular organelles : mitochondria , free ribosomes , ribosomes of the granular endoplasmic reticulum ;
C0014139
endocytosis
C0007634
cellular