Tissue and biomechanical analysis of bones of ovariectomized rats fed a high-fat diet

• Grant number: 14/25879-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2015
• End date: August 04, 2017
• Field of knowledge: Engineering - Biomedical Engineering
• Principal Investigator: Antônio Carlos Shimano
• Grantee: Gabriela Rezende Yanagihara
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated scholarship(s): 15/26142-1 - Image Processing and Analysis obtained by Scanning Electron Microscopy of bone of female obese and eutrophic rats, BE.EP.DR

Abstract

The relationship between fat mass and bone loss has been reported in several studies, but not yet an objective definition of this relationship. The propose of this research project is to assess what effects the fat diet early or late can exercise on bone of ovariectomized rats. The research project will be divided into two phases: Phase I- Preliminary study, which will evaluate what the effects of high fat diet immediately after weaning from infant Wistar rats (21 days old) and during five weeks (totaling 8 weeks age at which rats are given aged for removal of ovaries) . This step will consist of two groups: PAD (fed standard diet) and HIP (fed with high fat diet); Pahse II- will depend on the results of phase I. If the results of the preliminary study indicate that 5 weeks of high fat diet did not cause significant differences in the quality of bone tissue, then it will be used Methodology A: "Study of the effects of high fat diet early in bone tissue of ovariectomized rats, and if this diet will be able to accelerate the deleterious effects in the bone, caused by ovariectomy." This methodology will have 6 experimental groups: PAD/PAD45 and 90 (standard normal diet before and after ovariectomy and euthanized at 45 and 90 days), HIP/HIP45 an 90 (fat diet before and after ovariectomy and euthanasia with 45 and 90 days) and PAD/HIP45 and 90 (standard normal diet, before ovariectomy fat diet, and then sacrificed at 45 and 90 days). If the results of the preliminary study indicate that 5 weeks of high fat diet cause deleterious effects on bone, then it will be used methodology B: "Study of the effects of return to standard diet after ovariectomy in rats in early intake of high-fat diet." This methodology is also composed of 6 experimental groups , the first 4 being equal to that of Methodology A. The two different groups are: HIP/PAD45 and 90 (before ovariectomy fat diet, standard normal diet and then euthanized at 45 and 90 days). The analyzes will be performed: Analysis of insulin resistance, FSH analysis, of liver tissue, gene expression in bone by RT-PCR, bone densitometry, mechanical testing of trabecular and cortical bone, and Micro-CT.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

REZENDE YANAGIHARA, G.; CARMINATI SHIMANO, R.; ATSUKO TIDA, J.; SUZUKI YAMANAKA, J.; YASUYO FUKADA, S.; MARDEGAN ISSA, J. P.; SHIMANO, A. C.; TAVARES, JOAO MANUEL R. S.. Influence of high-fat diet on bone tissue: An experimental study in growing rats. Journal of Nutrition Health & Aging, v. 21, n. 10, p. 1337-1343, DEC 2017. (15/26142-1, 14/10733-8, 14/25879-8)

SHIMANO, R. C.; YANAGIHARA, G. R.; MACEDO, A. P.; YAMANAKA, J. S.; SHIMANO, A. C.; TAVARES, J. M. R. S.; ISSA, J. P. M.. Effects of high-impact exercise on the physical properties of bones of ovariectomized rats fed to a high-protein diet. SCANDINAVIAN JOURNAL OF MEDICINE & SCIENCE IN SPORTS, v. 28, n. 5, p. 1523-1531, MAY 2018. (15/16194-4, 14/10733-8, 14/25879-8, 15/26142-1)