title: [Effects of treadmill exercise on mRNA expression levels of osteoprotegerin, RANKL and RUNX2 in bone tissues of ovariectomized].
abstract: OBJECTIVE
  To observe the effect of treadmill exercise on the mRNA expression of osteoprotegerin, RANKL and RUNX2 in bone tissue of ovariectomized rat,and to investigate the mechanism of treadmill exercise for the preventing and treating postmenopausal osteoporosis.
  
  
  METHODS
  Thirty healthy adult SD rats which average weight was (270 +/- 10) g were randomly divided into 3 groups: sham-operation group, ovariectomized group and treadmill exercise group. Each group had 10 rats. After anesthesia, ovariectomized group and treadmill exercise treated group were operated by bilateral ovarian resection, sham group by sham operation. Sham-operation group and ovarian rats were normal breed. Rats in the exercise group were treated by running on treadmill for animal at 1 week after the operation. Running speed was 18 meters per minutes lasting 45 minutes in one day, and worked six days per week for 11 weeks. All rats were killed after 12 weeks. After decalcification, left femur head was made to paraffin slice and observed by inverted phase contrast microscope for histological examination. Total RNA were extracted from the right femur heads and the mRNA expression of OPG,RANKL and RUNX2 were examined by real time PCR.
  
  
  RESULTS
  The femur heads of ovariectomized group showed thin trabecular bone and less bone cells, meanwhile trabecular bone of exercise group looked thicker in histological examination. The mRNA expression of OPG (0.131 +/- 0.080), RANKL (8.013 +/- 3.550) and RUNX2 (3.245 +/- 5.090) was seen in the ovariectomized group. Meanwhile different results were found as the mRNA expression of OPG (0.566 +/- 0.260), RANKL (5.232 +/- 3.670) and RUNX2 (2.753 +/- 3.680) in the group of treadmill exercise. In compared with ovariectomized group, the mRNA expression of OPG in treadmill exercise increased and the result had statistical significance,whereas mRNA expression of RNAKL and RUNX2 decreased but the results had no statistical significance.
  
  
  CONCLUSIONS
  The effect of exercise treating postmenopausal osteoporosis is tightly correlated with the up-regulation of expression of OPG. This provides a new train of thought of postmenopausal osteoporosis treatment for the future study.
authors.affiliation: Department of Orthopaedics, Yijishan Hospital of Wannan Medical College, Wuhu 241000, Anhui, China. 13909636163@126.com
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, Yijishan Hospital of Wannan Medical College, Wuhu 241000, Anhui, China.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.affiliation: Department of Orthopaedics, Yijishan Hospital of Wannan Medical College, Wuhu 241000, Anhui, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000328:Adult; D000818:Animals; D015519:Bone Density; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics* / Q000378:metabolism; D005080:Exercise Test; D005081:Exercise Therapy; D005260:Female; D005269:Femur / Q000378:metabolism; D006801:Humans; D015663:Osteoporosis, Postmenopausal / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D053244:Osteoprotegerin / Q000235:genetics* / Q000378:metabolism; D010052:Ovariectomy; D053245:RANK Ligand / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D053244:Osteoprotegerin; D053245:RANK Ligand; C493717:Runx2 protein, rat