Lysosomal accumulation of intravenously administered hyaluronidase.

Rat tail tendon collagen fibrils disaggregated in the mild experimental conditions to sub-fibrillar structures. The smallest, most frequent (protofibrils) were of fairly constant thickness, 12-15 nm. They often arose from larger subfibrils ( > 25 nm) that were nevertheless much smaller than the parent fibril. The protofibrils retained a faint banding pattern. They were oriented helically. The 25 nm sub-fibrils had clearer banding patterns, in register with that of the parent fibril. Fixation by glutaraldehyde prevented disaggregation. Axial PG filaments were seen inside large collagen fibrils in aged human intercostal cartilage, rabbit annulus fibrosus, rat tail and turkey flexor digitorum tendons arranged regularly in bands across the fibril, often traversing the gap zone, roughly parallel to the main fibril axis. Other PG filaments followed a chord of the circular fibril cross-section, in parallel with other chordal filaments.