[Apoptotic cells and related factors in ovariectomized rat osteoporosis model].
OBJECTIVE
To investigate the status of apoptosis of osteoblast, osteoclast and the relative factors.


METHODS
Apoptotic cells were examined using in situ end labeling technique. Expressions of bcl-2, Fas and transforming growth factor(TGF) beta1 were observed with immunohistochemical method.


RESULTS
Positive expression rate (40.5 +/- 5.2)% of apoptosis cells was significantly increased in the osteoblast, but the expression rate of apoptosis cells (8.4 +/- 1.2)% was significantly decreased in the osteoclast of the post-ovariectomy rats than in the sham-operated rats. The expression of Fas was decreased in osteoclast (20.0%) and increased in osteoblast (80.0%) of the post-ovariectomized rats. The expression of TGFbeta1 was significantly decreased in the osteoclast (0) and the osteoblast (20.0%) of the post-ovariectomized rats. The above-mentioned targets in post-ovariectomized rats treated with nylestriol/levonorgestrel were close to those sham-operated rats (P > 0.05).


CONCLUSIONS
Bone loss in the post-ovariectomized rats is attributable to the lower level of estrogen so that the apoptosis cells were decreased in osteoclast but were increased in osteoblast. As a result, the process of bone absorption prevails over that of bone formation. Expression of TGFbeta1 depends on stimulation of estrogen. TGFbeta1 may stimulate apoptosis of osteoclast and restrain apoptosis of osteoblast. Fas can induce the apoptosis of osteoclast.
Li
D
D
Department of Pathology, The Second Affiliated Hospital, Hunan Medical University, Changsha 410011, China.
Wu
H
H
D000818:Animals; D017209:Apoptosis; D005260:Female; D007150:Immunohistochemistry; D010006:Osteoblasts / Q000473:pathology; D010010:Osteoclasts / Q000473:pathology; D010024:Osteoporosis / Q000378:metabolism / Q000473:pathology*; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D016212:Transforming Growth Factor beta / Q000378:metabolism; D053773:Transforming Growth Factor beta1; D019014:fas Receptor / Q000378:metabolism
C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D019014:fas Receptor