Leptin expression by heterotopic ossification-isolated tissue in rats with Achilles' tenotomy.
OBJECTIVE
To set up heterotopic ossification (HO) models according to McClure and determine whether leptin messenger ribonucleic acid (mRNA) and protein are expressed in HO-isolated tissue.


METHODS
This study was performed in the Department of Spine and Orthopedics, Southern Medical University, Guangzhou, China from November 2007 to June 2008. Thirty-six male rats were randomly divided into sham, partial achilles' tenotomy (PAT), and achilles' tenotomy (AT) groups, with 12 rats in each group. X-ray and histological examination were carried out to ensure the formation of HO at 5 and 10 weeks after operation. Specimens from achilles tendons and surrounding tissue were taken and processed. Meanwhile, the expression of leptin mRNA (5 and 10 weeks) and protein (10 weeks) in achilles tendons and the surrounding tissue were examined respectively using reverse transcription-polymerase chain reaction assay and immunohistochemical methods.


RESULTS
There were no leptin mRNA and protein expression in the sham and a weak expression in the PAT of Achilles tendons and surrounding tissue, whereas there was strong expression in the AT group.


CONCLUSIONS
Leptin is involved in the formation of HO, its mechanisms is related to induction of bone formation and maturation through a series of cellular events, including: proliferation/differentiation of many kinds of cells, collagen synthesis, mineralization, and vascularization of the extracellular matrix.
Department of Spine & Orthopedics, Nanfang Hospital of Southern Medical University, Guangdong Province, China.
Jun-Chang
JC
Xu
Tao
T
Wu
Gui-Hua
GH
Wu
Zhao-Ming
ZM
Zhong
Yong-Zhi
YZ
Tang
Jian-Ting
JT
Chen
D000125:Achilles Tendon / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D020738:Leptin / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009999:Ossification, Heterotopic; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D020738:Leptin; D012333:RNA, Messenger