Immobilization and cartilage transformation into bone in the embryonic chick
Article first published online: 27 JAN 2005
Copyright © 1972 Wiley-Liss, Inc.
The Anatomical Record
Volume 173, Issue 4, pages 391–403, August 1972
How to Cite
Haal, B. K. (1972), Immobilization and cartilage transformation into bone in the embryonic chick. Anat. Rec., 173: 391–403. doi: 10.1002/ar.1091730402
- Issue published online: 27 JAN 2005
- Article first published online: 27 JAN 2005
- Manuscript Accepted: 24 MAY 1972
- Manuscript Received: 6 MAR 1972
The fate of the secondary cartilage present on the membrane bones of the embryonic chick has been studied after immobilization. Immobilization was achieved by the in vivo injection of paralysing drugs (tubocurare or decamethonium), by grafting membrane bones onto the chorioallantoic membrane, or by organ-culturing membrane bones in vitro. In all three situations the cartilage was transformed into a bone-like tissue, the matrix losing its acid muco-polysaccharide, accumulating collagen and undergoing calcification. The chondrocytes shrank in size, came to resemble osteoblasts (osteocytes) and acquired alkaline phosphatase activity.
In normal development this cartilage is not transformed into bone but is partly replaced by bone and partly converted into a fibrocartilage which forms the definitive articular cartilage. Immobilization prevented this normal sequence.
Past studies on the transformation of cartilage to bone are reviewed and are seen to be adaptations of a highly labile tissue to functional demands.