the data strongly suggest that collagen fibrils found in cytoplasmic vacuoles of periosteal fibroblasts represent collagen taken up by phagocytosis , the integrity of cytoplasmic actin filament systems is a prerequisite for phagocytosis of collagen to occur , and thiol-proteinases , such as cathepsin b , l , and/or n , play an essential role in the digestion of internalized collagen .
C0010834
cytoplasmic
C0042219
vacuoles