Expression of osteocalcin in the patella of experimentally immobilized and remobilized rats

Pekka Kannus, L. Józsa, Martti Kvist, Teppo L N Järvinen, Vesa Matti Maunu, Timo Hurme, Markku Järvinen

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

The exact mechanisms by which mechanical loading-unloading affects bone tissue are mostly unknown. Recently, osteocalcin, a direct product of osteoblasts, has been shown to reflect the activity of the mineralization phase of the newly formed bone matrix, and therefore, the in situ detection of osteocalcin could be used for studying the effects of physical activity- inactivity on the osteoblast function or bone formation in the target bone. In this study, the effect of various loading states (immobilization and three forms of subsequent remobilization) on the in situ expression of osteocalcin in the rat patellas and their osteotendinous junctions was studied immunohistochemically using a polyclonal rat antiosteocalcin as the primary antibody. Following immobilization for 3 weeks, the immunoreactivity of osteocalcin was markedly decreased or was completely absent in all the patellar areas which normally show intense reaction as a sign of mineralization of the newly formed bone, that is, in the subperiosteal and subchondral regions, in the osteoid tissue that lies on the surface of the trabecular bone, and around the cortical lacunae. The same was true in the mineralized fibrocartilage zone of the osteotendinous junction of the quadriceps tendon. Free remobilization for 8 weeks (free cage activity) could not improve the situation, but after intensified remobilization of the same duration (low and especially high intensity treadmill running) high osteocalcin expression was observed in the above-mentioned anatomic sites. These findings indicate that formation of new bone tissue is rapidly regulated by the loading states of the bone. Higher than normal activity seems to be needed to restore the bone formation from the disuse-induced depression to normal.

Original languageEnglish
Pages (from-to)79-87
Number of pages9
JournalJournal of Bone and Mineral Research
Volume11
Issue number1
Publication statusPublished - Jan 1996

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Patella
Osteocalcin
Bone and Bones
Osteoblasts
Osteogenesis
Immobilization
Fibrocartilage
Bone Matrix
Running
Tendons
Antibodies

ASJC Scopus subject areas

  • Surgery

Cite this

Kannus, P., Józsa, L., Kvist, M., Järvinen, T. L. N., Maunu, V. M., Hurme, T., & Järvinen, M. (1996). Expression of osteocalcin in the patella of experimentally immobilized and remobilized rats. Journal of Bone and Mineral Research, 11(1), 79-87.

Expression of osteocalcin in the patella of experimentally immobilized and remobilized rats. / Kannus, Pekka; Józsa, L.; Kvist, Martti; Järvinen, Teppo L N; Maunu, Vesa Matti; Hurme, Timo; Järvinen, Markku.

In: Journal of Bone and Mineral Research, Vol. 11, No. 1, 01.1996, p. 79-87.

Research output: Contribution to journalArticle

Kannus, P, Józsa, L, Kvist, M, Järvinen, TLN, Maunu, VM, Hurme, T & Järvinen, M 1996, 'Expression of osteocalcin in the patella of experimentally immobilized and remobilized rats', Journal of Bone and Mineral Research, vol. 11, no. 1, pp. 79-87.
Kannus, Pekka ; Józsa, L. ; Kvist, Martti ; Järvinen, Teppo L N ; Maunu, Vesa Matti ; Hurme, Timo ; Järvinen, Markku. / Expression of osteocalcin in the patella of experimentally immobilized and remobilized rats. In: Journal of Bone and Mineral Research. 1996 ; Vol. 11, No. 1. pp. 79-87.
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