オオナル　カズヒロ   Kazuhiro Onaru   大成　和寛    所属   川崎医科大学  医学部 臨床医学　脊椎・関節整形外科学    職種   講師
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	Effect of swimming exercise on three-dimensional trabecular bone microarchitecture in ovariectomized rats
掲載誌名	正式名：Journal of applied physiology 略　 称：J Appl Physiol ISSNコード：00218987
巻・号・頁	119(9),pp.990-997
著者・共著者	Yong-In Ju, Teruki Sone, Kazuhiro Ohnaru, Censure Tanaka, Masao Fukunaga
発行年月	2015/11
概要	Swimming is generally considered ineffective for increasing bone mass in humans, at least compared with weight-bearing sports. However, swimming exercise has sometimes been shown to have a strong positive effect on bone mass in small animals. This study investigated the effects of swimming on bone mass, strength, and microarchitecture in ovariectomized (OVX) rats. OVX or sham-operations were performed on 18-week-old female Fisher-344 rats. Rats were randomly divided into 4 groups: sham sedentary (Sham-CON); sham swimming-exercised (Sham-SWI); OVX sedentary (OVX-CON); and OVX swimming-exercised (OVX-SWI). Rats in exercise groups performed swimming in a water bath for 60 min/day, 5 days/week, for 12 weeks. Bone mineral density (BMD) in right femurs was analyzed using dual-energy X-ray absorptiometry. Three-dimensional trabecular architecture at the distal femoral metaphysis was analyzed using microcomputed tomography (micro-CT). Geometrical properties of diaphyseal cortical bone were evaluated in the mid-femoral region using micro-CT. The biomechanical properties of femurs were analyzed using 3-point bending. Femoral BMD was significantly decreased following ovariectomy. This change was suppressed by swimming. Trabecular bone thickness, number, and connectivity were decreased by ovariectomy, whereas structure model index (i.e., ratio of rod-like to plate-like trabeculae) increased. These changes were also suppressed by swimming exercise. Femurs displayed greater cortical width and maximum load in SWI groups than in CON groups. Together, these results demonstrate that swimming exercise drastically alleviated both OVX-induced decreases in bone mass and mechanical strength, and the deterioration of trabecular microarchitecture in rat models of osteoporosis.
DOI	10.1152/japplphysiol.00147.2015
PMID	26338454