The effects of age and sex on the expression of aromatase in the rat temporomandibular joint.
OBJECTIVE
To investigate the expression of aromatase in temporomandibular joints(TMJs) of male and female rats of different ages.


METHODS
The expression of aromatase in terms of protein and mRNA was examined by immunohistochemistry, Western blot, and in situ hybridization in the TMJs of Sprague-Dawley rats. The expression level of aromatase protein was also quantified by the density of aromatase-positive chondrocytes in TMJ condylar cartilage. A tritiated water assay was used to analyze the activity of aromatase in cartilage chondrocytes.


RESULTS
Strong aromatase protein and mRNA hybridization signals were detected in hypertrophic and mature chondrocytes in all the cases examined. The density of aromatase-positive chondrocytes was relatively stable at higher levels before 8 weeks of age. The density decreased gradually in females after 8 weeks of age but not in males.


CONCLUSIONS
These results demonstrate that aromatase is expressed intensely in condylar cartilage and suggest that it may play an important role in pathophysiological mechanisms in condylar cartilage.
Yu
Shi-Bin B
SB
Department of Oral Anatomy and Physiology, Hospital of Stomatology, Fourth Military Medical University, Xi'an, China
Wang
Mei-Qing
MQ
Zhao
Wei
W
Cao
Hong-Tao
HT
Liu
Yan-Li
YL
D000367:Age Factors; D000818:Animals; D001141:Aromatase / Q000096:biosynthesis*; D015153:Blotting, Western; D002358:Cartilage, Articular / Q000201:enzymology; D019902:Chondrocytes / Q000201:enzymology; D004967:Estrogens / Q000096:biosynthesis; D005260:Female; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012737:Sex Factors; D013704:Temporomandibular Joint / Q000201:enzymology*
D004967:Estrogens; D001141:Aromatase