Effects of high-impact exercise on the physical properties of bones of ovariectomized rats fed to a high-protein diet

• Autor(a) principal: Roberta Carminati Shimano
• Data de Publicação: 2018
• Outros Autores: Gabriela Rezende Yanagihara, Ana Paula Macedo, Jessica Suzuki Yamanaka, Antônio Carlos Shimano, João Manuel R. S. Tavares, João Paulo Mardegan Issa
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://hdl.handle.net/10216/111710
• topic: Ciências da Saúde, Ciências da engenharia e tecnologias; Health sciences, Engineering and technology

The aim of this study was to evaluate the effects of high-impact physical exercise as a prophylactic and therapeutic means in osteopenic bones of rats submitted to ovariectomy and protein diet intake. A total of 64 Wistar rats were divided into eight groups (n=8 each), being: OVX, ovx, standard diet and sedentary; OVXE, ovx, standard diet and jump; OVXP, ovx, high-protein diet and sedentary; and OVXEP, ovx, high-protein diet and jump; SH, sham, standard diet and sedentary; SHE, sham, standard diet and jump; SHP, sham, high-protein diet and sedentary; and SHEP, sham, high-protein diet and jump. OVX surgery consists of ovariectomy, and sham was the control surgery. The jumping protocol consisted of 20 jumps/day, 5days/week. The bone structure was evaluated by densitometry, mechanical tests, histomorphometric, and immunohistochemical analyses. A high-protein diet resulted in increased bone mineral density (P=.049), but decreased maximal load (P=.026) and bone volume fraction (P=.023). The benefits of physical exercise were demonstrated by higher values of the maximal load in the trained groups compared to the sedentary groups (P<.001). The sham groups had decreased immunostaining of osteocalcin (P=.004) and osteopontin (P=.010) compared to ovx groups. However, the high-protein diet (P=.005) and jump exercise (P=.017) resulted in lower immunostaining of osteopontin compared to the standard diet and sedentary groups, respectively. In this experimental model, it was concluded that ovariectomy and a high-fat diet can negatively affect bone tissue and the high-impact exercise was not enough to suppress the deleterious effects caused by the protein diet and ovariectomy.