Bone Quality of the Femoral Mid-Shaft of Ovariectomized Rats Fed a Low-Mineral Diet

Abstract

Ovariectomized (OVX) rats are accepted models for screening potential therapeutic agents for osteoporosis. A low-mineral diet accelerates bone loss in OVX rats. This study aimed to determine changes in bone quality caused by ovariectomy or by combined ovariectomy and a mineral-deficient diet. Forty-eight female Wistar rats, aged 19 weeks, were distributed into 3 groups (n = 16 per group): Group 1: (control) subjected to a sham operation and administered a normal diet, Group 2: OVX rats fed a normal diet, and Group 3: OVX rats fed a low-mineral diet. The rats were sacrificed after 4, 8, 16, and 24 weeks. The density distribution and volume of the femur mid-shaft were evaluated to assess bone quality using micro-computed tomography and polarized microscopy. Bone strength was evaluated using a 3-point bending test. Bone density distribution, bone volume, and strength were the lowest for Group 3 and the highest for Group 1 at all times. Using a polarized microscope, we found that the tubular structures of the Haversian and Volkmann's canals were decreased in Group 3 compared with those of Groups 1 and 2. Positive correlations were noted between fracture load and bone density, fracture load and bone volume, and bone volume and bone density in Group 3, and between bone density and volume, and bone volume and fracture load in Groups 2 and 3. We conclude that estrogen deficiency (ovariectomy) and mineral deficiency had separate as well as combined effects on bone quality.

A New Synthetic Diet Increased Bone Mineral Density and Strength of Ovariectomized Rat

“…The present study using rats demonstrates the effects of estrogen deficiency (ovariectomy) alone or combined with SD on bone quality (density and strength) as assessed by 3D-mapand the 3-point bending test. The analytical system employing micro-CT and TRI/3D used in this study is capable of 3D visualization of the bone structure, qualitative analysis by pseudocolor rendering, and quantitative analysis of BMD [7][8][9]. In conventional micro-CT imaging, black and white images are evaluated because the color intensity representing X-ray penetration and non-penetration through materials is judged.…”

Structure Model Index Changes in the Femoral Epiphyseal Region on Micro-Computed Tomography Caused by a Supplement Diet in Ovariectomized Rats

“…OVX groups reportedly show greater bone resorption than bone formation due to reduced estrogen secretion, leading to decreased BMD and bone strength 9) . However, although the HMD group was also exposed to an environment that reduces estrogen secretion, SMIs were higher in the HMD group than in the NMD group.…”

“…[8][9][10] Osteoporosis is a systemic disease that results in reduced bone mass and poor trabecular bone structure. 11,12) It is defined as "a skeletal disorder characterized by compromised bone strength predisposing to an increased risk of fracture".…”

“…Thus, in previous studies, we analyzed bone samples with micro-CT imaging and subsequently performed bending tests and sectioning, thereby permitting multiple analyses on the same sample [6][7][8][9][10] .…”

Legendary Women in Dentistry: Racquel Z. LeGeros

“…This pattern of recognition by a multidisciplinary variety of funding sources endured and continued to produce strong findings. A 2012 investigation, co-funded by the NIH, National Institute of Arthritis and Musculoskeletal and Skin Disease (NIAMS), and the Ministry of Education, Culture, Sports, Science, and Technology of Japan, Suzuki et al (2012) reported dietary estrogen contributed to bone loss and were supported by later investigations (Nakada et al, 2011). As such, LeGeros was attracting multidisciplinary funding from international sources.…”