Effects of high‐impact exercise on the physical properties of bones of ovariectomized rats fed to a high‐protein diet. (8th February 2018)

• Record Type: Journal Article
• Authors: Shimano, R. C.; Yanagihara, G. R.; Macedo, A. P.; Yamanaka, J. S.; Shimano, A. C.; Tavares, J. M. R. S.; Issa, J. P. M.
• Is Part Of: Scandinavian journal of medicine & science in sports. Volume 28:Number 5(2018)
• Page Start: 1523
• Page End: 1531
• Publication Date: 2018-02-08
• Subjects: bone diseases -- jump and nutrition -- metabolic -- ovariectomy; Sports medicine -- Periodicals; Sports -- Physiological aspects -- Periodicals; Sports -- Periodicals; 617.1027
• DOI: 10.1111/sms.13058
• Languages: English
• ISSNs: 0905-7188

Abstract

Abstract : 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, 5 days/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.