title: The osteogenic effects of swimming on bone mass, strength, and microarchitecture in rats with unloading-induced bone loss.
abstract: The effect of nonweight-bearing exercise on osteoporotic bones remains controversial and inconclusive. The purpose of this study was to evaluate the effects of swimming on osteoporotic tibias of rats submitted to hindlimb suspension. Initially, 20 Wistar rats were used to confirm a significant bone loss following 21 days of unloading. Thirty rats were then divided into 3 groups and followed during 51 days: CON (nonsuspended rats), S + WB (suspended rats for 21 days and then released for regular weight-bearing) and, S + Swim (suspended rats for 21 days and then released from suspension and submitted to swimming exercise). We observed that swimming exercise was effective at fully recovering the bone deterioration caused by suspension, with significant increments in BMD, bone strength and bone volume. On the other hand, regular weight-bearing failed at fully restoring the bone loss induced by unloading. These results indicate that swimming exercise may be a potential tool to improve bone density, strength, and trabecular volume in tibias with bone loss induced by mechanical unloading in suspended rats. We conclude that this modality of activity could be beneficial in improving bone mass, strength, and architecture in osteoporotic individuals induced by disuse, such as bed rest or those exposed to microgravity, who may not be able to perform weight-bearing exercises.
authors.affiliation: Department of Biomechanics, Medicine and Rehabilitation, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Jose Batista
authors.initials: JB
authors.lastname: Volpon
authors.affiliation: Department of Biomechanics, Medicine and Rehabilitation, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Adriana Valadares
authors.initials: AV
authors.lastname: Silva
authors.affiliation: Department of Biomechanics, Medicine and Rehabilitation, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Mauricio Jose
authors.initials: MJ
authors.lastname: Falcai
authors.affiliation: Department of Production and Health Animal, University of São Paulo State, Brazil.
authors.forename: Mario Jefferson Quirino
authors.initials: MJ
authors.lastname: Louzada
authors.affiliation: Department of Biomechanics, Medicine and Rehabilitation, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Ariane
authors.initials: A
authors.lastname: Zamarioli
authors.affiliation: Department of Biomechanics, Medicine and Rehabilitation, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Bruna Gabriela Dos Santos
authors.initials: BG
authors.lastname: Kotake
authors.affiliation: Department of Morphology, Physiology and Basic Pathology, University of São Paulo, Brazil.
authors.forename: João Paulo Mardegan
authors.initials: JP
authors.lastname: Issa
mesh_terms: D000818:Animals; D015519:Bone Density; D019417:Hindlimb Suspension; D010024:Osteoporosis / Q000473:pathology* / Q000628:therapy*; D010805:Physical Conditioning, Animal; D017208:Rats, Wistar; D013550:Swimming; D013977:Tibia / Q000033:anatomy & histology* / Q000502:physiology*; D016474:Weight-Bearing
keywords: bone tissue; hindlimb suspension; nonweight-bearing exercise; osteoporosis