title: Multiscale investigation on the effects of additional weight bearing in combination with low-magnitude high-frequency vibration on bone quality of growing female rats.
abstract: This study aimed to explore the effects of additional weight bearing in combination with low-magnitude high-frequency vibration (LMHFV; 45 Hz, 0.3 g) on bone quality. One hundred twenty rats were randomly divided into ten groups; namely, sedentary (SED), additional weight bearing in which the rat wears a backpack whose weight is x% of the body weight (WBx; x = 5, 12, 19, 26), basic vibration (V), and additional weight bearing in combination with LMHFV in which the rat wears a backpack whose weight is x% of the body weight (Vx; x = 5, 12, 19, 26). The experiment was conducted for 12 weeks, 7 days per week, and 15 min per day. A three-point bending mechanical test, micro computed tomography, and a nanoindentation test were used. Serum samples were analyzed chemically. Failure load in V19 rats was significantly lower than that in SED rats (P < 0.05). Vx (x = 5, 12, 19, 26) rats showed poor microarchitectures. The content of tartrate-resistant acid phosphatase 5b was significantly higher in Vx (x = 5, 12, 19, 26) rats than that in SED rats (P < 0.05). V26 rats demonstrated comparatively better nanomechanical properties of materials than the other vibrational groups. Additional weight bearing in combination with LMHFV negatively affected the macromechanical properties and microarchitecture of bone. Heavy additional weight bearing, such as 26% of body weight, in combination with LMHFV was able to improve the nanomechanical properties of growing bone material compared with LMHFV. A combined mechanical stimulation was used, which may provide useful information to understand the mechanism of this mechanical stimulation on bone.
authors.affiliation: Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China.
authors.forename: Tianlong
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China.
authors.forename: Jiazi
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Fang
authors.affiliation: Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China. gonghe@jlu.edu.cn.
authors.forename: He
authors.initials: H
authors.lastname: Gong
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D001696:Biomechanical Phenomena; D001835:Body Weight; D015519:Bone Density; D001846:Bone Development; D001842:Bone and Bones / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D002118:Calcium / Q000097:blood; D055119:Elastic Modulus; D005260:Female; D005269:Femur / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology; D006244:Hardness; D021621:Imaging, Three-Dimensional; D009132:Muscles / Q000033:anatomy & histology / Q000502:physiology; D009929:Organ Size; D010758:Phosphorus / Q000097:blood; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D000071681:Tartrate-Resistant Acid Phosphatase / Q000097:blood; D014732:Vibration; D016474:Weight-Bearing; D055114:X-Ray Microtomography
chemical_list: D010758:Phosphorus; D000469:Alkaline Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D002118:Calcium
keywords: Additional weight bearing; Bone quality; Growing; Low-magnitude high-frequency vibration; Multiscale