Influence of exercise on bone remodeling-related hormones and cytokines in ovariectomized rats: a model of postmenopausal osteoporosis

Lihui Li; Xi Chen; Shuang Lv; Miaomiao Dong; Li Zhang; Jiaheng Tu; Jie Yang; Lingli Zhang; Yinan Song; Leiting Xu; Jun Zou

doi:10.1371/journal.pone.0112845

Influence of exercise on bone remodeling-related hormones and cytokines in ovariectomized rats: a model of postmenopausal osteoporosis

PLoS One. 2014 Nov 13;9(11):e112845. doi: 10.1371/journal.pone.0112845. eCollection 2014.

Authors

Lihui Li¹, Xi Chen², Shuang Lv¹, Miaomiao Dong¹, Li Zhang¹, Jiaheng Tu¹, Jie Yang¹, Lingli Zhang¹, Yinan Song¹, Leiting Xu³, Jun Zou⁴

Affiliations

¹ School of Kinesiology, Shanghai University of Sport, Shanghai, China.
² School of Kinesiology, Shanghai University of Sport, Shanghai, China; School of Sports Science, Wenzhou Medical University, Wenzhou, China.
³ School of Kinesiology, Shanghai University of Sport, Shanghai, China; Medical School of Ningbo University, Ningbo, China.
⁴ Scientific Research Department, Shanghai University of Sport, Shanghai, China.

Abstract

This study aims to explore the effects of exercise on postmenopausal osteoporosis and the mechanisms by which exercise affects bone remodeling. Sixty-three Wistar female rats were randomly divided into five groups: (1) control group, (2) sham-operated group, (3) OVX (Ovariectomy) group, (4) DES-OVX (Diethylstilbestrol-OVX) group, and (5) Ex-OVX (Exercise-OVX) group. The rat osteoporosis model was established through ovariectomy. The Ex-OVX rats were made to run 251.2 meters every day, 6 d/wk for 3 months in a running wheel. Trabecular bone volume (TBV%), total resorption surface (TRS%), trabecular formation surface (TFS%), mineralization rate (MAR), bone cortex mineralization rate (mAR), and osteoid seam width (OSW) were determined by bone histomorphometry. The mRNA and protein levels of interleukin-1β (IL-1β2), interleukin-6 (IL-6), and cyclooxygenase-2 (Cox-2) were determined by in situ hybridization and immunohistochemistry, respectively. Serum levels of estrogen estradiol (E2), calcitonin (CT), osteocalcin (BGP), and parathyroid hormone (PTH) were determined by ELISA assays. The investigation revealed that compared to the control and the sham-operated groups, the OVX group showed significantly lower levels of TBV%, E2, and CT, but much higher levels of TRS%, TFS%, MAR, OSW, BGP, and PTH. The Ex-OVX group showed increased TBV% and serum levels of E2 and CT compared to the OVX group. Ovariectomy also led to a significant increase in IL-1β mRNA and protein levels in the bone marrow and IL-6 and Cox-2 protein levels in tibias. In addition, the Ex-OVX group showed lower levels of IL-1 mRNA and protein, IL-6 mRNA, and Cox-2 mRNA and protein than those in the OVX group. The upshot of the study suggests that exercise can significantly increase bone mass in postmenopausal osteoporosis rat models by inhibiting bone resorption and increasing bone formation, especially in trabecular bones.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Bone Density
Bone Remodeling*
Cytokines / metabolism*
Disease Models, Animal
Female
Hormones / metabolism*
Humans
Osteoporosis, Postmenopausal* / metabolism
Osteoporosis, Postmenopausal* / pathology
Osteoporosis, Postmenopausal* / therapy
Ovariectomy*
Physical Conditioning, Animal*
Rats
Rats, Wistar

Substances

Cytokines
Hormones

Grants and funding

This work was supported by Shanghai Key Lab of Human Sport Competence Development and Maintenance (Shanghai University of sport) (NO. 11DZ2261100), The National Natural Science Foundation of China (Grant No. 81170323). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.