Microscopic alterations in the physis of long bones in response to hind limb immobilization in the rat

Citation
I. Cohen et al., Microscopic alterations in the physis of long bones in response to hind limb immobilization in the rat, ISR MED ASS, 1(3), 1999, pp. 161-164
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
General & Internal Medicine
Journal title
ISRAEL MEDICAL ASSOCIATION JOURNAL
ISSN journal
1565-1088 → ACNP
Volume
1
Issue
3
Year of publication
1999
Pages
161 - 164
Database
ISI
SICI code
1565-1088(199911)1:3<161:MAITPO>2.0.ZU;2-6
Abstract
Background: The growth plate increases its activity in response to exercise . Likewise, decreased physical activity exerts a negative effect on bone gr owth and development, leading to rarefaction of the subepiphyseal bone. Lim b immobilization inhibits the growth plate's activity, indirectly shown by a recorded arrest in longitudinal growth of the long bones. However, there is no direct evidence concerning the growth plate itself. Objective: To determine whether the growth plate exhibits measurable micros tructural changes in response. to decreased levels of physical activity. Methods: Histomorphometric analysis was used to qualitatively and quantitat ively assess the changes in the epiphyseal plate in response to single hind limb immobilization in the rat. In 16 of 25 Sprague-Dawley male rats the l eft hind limb was immobilized for 3 weeks; the remaining 9 rats served as c ontrols, The left proximal tibia of each animal was examined by computerize d image analysis. Results: There was a decrease in epiphyseal height, cell column density and subepiphyseal trabecular area all indices of growth plate activity. Metaph yseal cortical thickness was also depressed, thereby confirming the efficac y of the immobilization method applied, Conclusions: Limb immobilization in the rat induces inhibitory histological changes in the epiphyseal growth plate, which are in contrast to the excit atory microscopic changes seen with exercise. These changes can be assessed quantitatively, Their potential for reversibility remains to be determined by future experiments.