[The morphology of the cells in the cartilage of rabbit mandibular condyle].
OBJECTIVE
To study the tissue layers and their function of the cartilage in mandibular condyle in rabbits.


METHODS
Six adult Japanese white rabbits were subjected. Their temporomandibular joints were studied by immunohistochemistry for FGFR3 and PCNA, and in situ hybridization for aggrecan and collagen II mRNA expression, as well as ultrastructure.


RESULTS
The upper proliferative cells did not express FGFR3, but the lower proliferative cells expressed FGFR3. Only few cells in the upper proliferative layer were PCNA positive, but all cells in the lower proliferative layer were positive for PCNA. No collagen II mRNA expression was found in the upper proliferative cell, but aggrecan and collagen II mRNA coexpressed in the lower proliferative layer. The cells in both layers were different in ultrastructure.


CONCLUSIONS
The cartilage in mandibular condyle should have the 5 following tissue layer: fibrous layer, proliferative layer, transitional layer, cartilaginous layer and calcified cartilaginous layer. The cells in the proliferative layer are undifferentiated and the cells in the differentiated layer are prechondrocytes.
Gu
Zhi-Yuan
ZY
Hospital of Stomatology, Zhejiang University. Hangzhou 310006, Zhejiang Province, China. gzy@zju.edu.cn
Hu
Ying
Y
Zhang
Yin-Kai
YK
Feng
Jian-Ying
JY
Hu
Ji-An
JA
Zhang
Zheng-Kang
ZK
D053674:Aggrecans / Q000378:metabolism; D000818:Animals; D002356:Cartilage / Q000166:cytology*; D002454:Cell Differentiation; D019902:Chondrocytes / Q000378:metabolism / Q000648:ultrastructure*; D024043:Collagen Type II / Q000378:metabolism; D008335:Mandibular Condyle / Q000166:cytology*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011817:Rabbits; D051498:Receptor, Fibroblast Growth Factor, Type 3 / Q000378:metabolism
D053674:Aggrecans; D024043:Collagen Type II; D018809:Proliferating Cell Nuclear Antigen; D051498:Receptor, Fibroblast Growth Factor, Type 3