title: [Effect of different types of jumps on the expressions of IL-6, OPG and RANKL in rat tibia].
abstract: OBJECTIVE
  To investigate the effect of different types of jumps on the expressions of interleukin 6 (IL-6), osteoprotegerin(OPG), ligand of receptor activator of NF-κB(RANKL) genes related to bone metabolism in rat tibia, and explore the molecular mechanism underlying bone destruction associated with over-loading jumping.
  
  
  METHODS
  Twenty-four male SD rats were randomly assigned to control group (C), jump group (J) and loading jump group (JL), 8 rats in each group. J group participated in incremental load training. The rats in JL group carried loads that were 5% of their body mass. Same training plan was used in J and JL groups, while control group was not treated. The experiment was completed after 6 weeks. The serum samples were collected and assayed for the contents of alkaline phosphatase (ALP) and tartrate resistant acid phosphatase (TRACP). One-side tibia was used for paraffin section and HE staining, and the other side was used for real time quantitative PCR(qRT-PCR) to detect the expressions of IL-6, OPG and RANKL mRNA.
  
  
  RESULTS
  Compared with control group and J group, the collagen fibers in periost was more disordered in JL group. We further observed a more serious damage of the cortical bone and increased cavities in JL group. The serum ALP levels in JL group were significantly higher than those in control and J groups (P<0.05). The serum TRACP levels in JL and J groups were significantly higher compared to control group (P<0.05). Furthermore, there was a significantly higher expression level of IL-6 in both jump groups (P<0.01), while the JL group had a higher IL-6 expression compared with J group (P<0.01). There was a higher expression of OPG mRNA in JL and J groups (P<0.05). The highest expression level of OPG was observed in J group. The expression level of RANKL was significantly higher in JL group compared with control and J groups (P<0.01).
  
  
  CONCLUSIONS
  After loading jump for 6 weeks, the expressions of IL-6 and RANKL were markedly elevated in rat tibia, suggesting that IL-6 and RANKL might be involved in the process of bone destruction due to increased bone turnover.
authors.affiliation: Institute of Biotechnology, Soochow University, Suzhou 215007; School of Biology and Basic Medical Science, Medical College, Soochow University, Suzhou 215123, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.affiliation: School of Physical Education, Soochow University, Suzhou 215021, China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School of Physical Education, Soochow University, Suzhou 215021, China.
authors.forename: Shengcun
authors.initials: S
authors.lastname: Li
mesh_terms: D000135:Acid Phosphatase / Q000097:blood; D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D015870:Gene Expression; D015850:Interleukin-6 / Q000235:genetics*; D007527:Isoenzymes / Q000097:blood; D008297:Male; D053244:Osteoprotegerin / Q000235:genetics*; D010805:Physical Conditioning, Animal / Q000009:adverse effects / Q000379:methods / Q000502:physiology*; D053245:RANK Ligand / Q000235:genetics*; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000071681:Tartrate-Resistant Acid Phosphatase; D013977:Tibia / Q000378:metabolism*; D013997:Time Factors
chemical_list: D015850:Interleukin-6; D007527:Isoenzymes; D053244:Osteoprotegerin; D053245:RANK Ligand; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase