Summary
It is generally accepted that osteoclasts are responsible for the breakdown and removal of bone matrix constituents. However, very little is known about the fate of osteocytes during bone resorption. In the present study we have examined sites of bone destruction in calvaria of young rats aged 4–9 days in the hope of obtaining information on the fate of osteocytes. Decalcified glutaraldehyde-formaldehyde-fixed specimens were prepared for ultrathin section electron microscopy. When sequentially arranged, the images obtained suggest that osteoclasts engulf and destroy osteocytes during bone degradation. We propose that the following sequence of events takes place when a lacuna is opened up by an osteoclast: (1) When the osteoclast comes in contact with an osteocyte, the villi of the ruffled border become flat and broad. (2) Long osteoclastic extensions surround the osteocyte. (3) The osteocyte is subsequently internalized with apparent degradation.
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References
Bonucci E (1981) New knowledge on the origin, function and fate of osteoclasts. Clin Orthop 158:252–269
Cameron DA (1972) The ultrastructure of bone. In: Bourne GH (ed) The biochemistry and physiology of bone, vol 1. Academic Press, London, pp 191–236
Chambers TJ (1985) The pathobiology of the osteoclast. J Clin Pathol 38:241–252
Hancox NM (1972) The biology of bone. Cambridge University Press, Cambridge
Jones SJ, Boyde A, Ali NN, Maconnachie E (1985) A review of bone cell and substratum interaction. An illustration of the role of scanning electron microscopy. Scanning 7:5–24
Marks SC, (1983) The origin of the osteoclasts: evidence, clinical implications and investigative challenges of an extraskeletal source. J Pathol 12:226–256
Vaes G (1968) On the mechanism of bone resorption. J Cell Biol 39:676–697
Arey LB (1919) The origin, growth and fate of osteoclasts and their relation to bone resorption. Am J Anat 26:315
Gothlin G, Ericsson JLE (1976) The osteoclast. Review of the ultrastructure, origin and structure-function relationship. Clin Orthop Rel Res 120:201–231
Tonna EA (1972) An electron microscopic study of osteocyte release during osteoclasis in mice of different ages. Clin Orthop Rel Res 87:311–317
Weinman JP, Sicher H (1947) Bone and Bones. Fundamentals of bone physiology. Henry Kimpton, London
Katchburian E, Holt SJ (1972) Studies on development of ameloblasts. I. Fine structure. J Cell Sci 2:415–447
Baron R, Neff L, Brown R, Courtoy PJ, Louvar D, Farquhar MG (1988) Polarized secretion of lysosomal enzymes: co-distribution of cation-independent mannose-6-phosphate receptors and lysosomal enzymes along the osteoclast exocytic pathway. J Cell Biol 106:1863–1872
Baron R, Neff L, Louvar D, Courtoy PJ (1985) Cell-mediated acidification and bone resorption: evidence for a low PH in resorbing lacunae and localization of a 100 KD lysosomal membrane protein at the osteoclast ruffled border. J Cell Biol 101:2210–2222
Lucht U (1971) Acid phosphatase of osteoclasts demonstrated by electron microscopic histochemistry. Histochimie 28:103–117
Delaisse JM, Eckout Y, Vaes G (1980) Inhibition of bone resorption in culture by inhibitors of thiol proteinases. Biochem J 192:365–368
Doty SB, Shofield BH (1976) Enzyme histochemistry of bone and cartilage cells. In: Progress in histochemistry and cytochemistry vol 8. Stuttgart, pp 10–26
Horton MA, Rimmer EF, Moore A, Chambers TJ (1985) On the origin of the osteoclasts; cell surface phenotype of rodent osteoclasts. Calcif Tissue Int 37:46–50
Jotereau FV, Le Douarin NM (1978) The developmental relationship between osteocytes and osteoclasts. A study using the quail-chick nuclear marker in endocranial ossification. Dev Biol 63:253–265
Owen MJ (1963) Cell population kinetics of an osteogenic tissue. J Cell Biol 19:19–32
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Elmardi, A.S., Katchburian, M.V. & Katchburian, E. Electron microscopy of developing calvaria reveals images that suggest that osteoclasts engulf and destroy osteocytes during bone resorption. Calcif Tissue Int 46, 239–245 (1990). https://doi.org/10.1007/BF02555002
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DOI: https://doi.org/10.1007/BF02555002