Author:
Ju Y-I.,Sone T.,Okamoto T.,Fukunaga M.
Abstract
Three-dimensional trabecular architecture was investigated in the femora of tail-suspended young growing rats, and the effects of jump exercise during remobilization were examined. Five-week-old male Wistar rats ( n = 35) were randomly assigned to five body weight-matched groups: tail-suspended group (SUS; n = 7); sedentary control group for SUS (SCON; n = 7); spontaneous recovery group after tail suspension (S+RCON, n = 7); jump exercise group after tail suspension (S+RJUM; n = 7); and age-matched control group for S+RCONand S+RJUMwithout tail suspension and exercise (SCON+RCON; n = 7). Rats in SUS and SCONwere killed immediately after tail suspension for 14 days. The jump exercise protocol consisted of 10 jumps/day, 5 days/wk, and jump height was 40 cm. Bone mineral density (BMD) of the femur and three-dimensional trabecular bone architecture at the distal femoral metaphysis were measured. Tail suspension induced a 13.6% decrease in total femoral BMD ( P < 0.001) and marked deterioration of trabecular architecture. After 5 wk of free remobilization, femoral BMD, calf muscle weight, and body weight returned to age-matched control levels, but trabeculae remained thinner and less connected. On the other hand, S+RJUMrats showed significant increases in trabecular thickness, number, and connectivity compared with S+RCONrats (62.8, 31.6, and 24.7%, respectively; P < 0.05), and these parameters of trabecular architecture returned to the levels of SCON+RCON. These results indicate that suspension-induced trabecular deterioration persists after remobilization, but jump exercise during remobilization can restore the integrity of trabecular architecture and bone mass in the femur in young growing rats.
Publisher
American Physiological Society
Subject
Physiology (medical),Physiology
Cited by
23 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献