Bone Structure In Rats Research Articles

Physical and chemical characterization of femur during and after body development period in male and female rats.

The aim of this study was to determine the physical and chemical characteristics of the bone structures during four developmental periods. Forty Wistar Albino rats (20 male and 20 female) were divided into four groups including prepubertal period (group I), period between adolescence and adulthood (group II) and later (young adult period as group III and old adult period as group IV). The bones were analysed by morphometric measurements, XRF (X-ray fluorescence) analysis for mineral levels and BET analysis (Brunaurer-Emmett-Teller) for surface area and porosity. In morphometric measurements, the GL (greatest length) and the GLC (greatest length from caput femoris) values increased gradually from the first to the fourth group, and these values were higher in the males than the females. Phosphorus and calcium values were higher in the males in adult groups (third and fourth) compared to that for the females; however, they were higher in the females in groups up to adulthood (first and second). While the Ca/P ratio reached the highest value in the second group in the male, it decreased gradually afterwards. In females, the rate, which was close to each other in the first three groups, increased in the fourth group. Surface area size in the female and the male rats was the highest in the second group. In conclusion, changes in the rat bone structure during the development and adulthood periods of the body were revealed, and it was determined that the gender factor was effective in these changes.

Analysis of Pelvic Bone of Ovariectomized Rats using Infrared and Raman Spectroscopies

Osteoporosis is a bone disease that generally occurs in postmenopausal women. Osteoporosis can be studied using an animal model such as rats because rat bone structure is similar to human bone structure. This research aimed to analyze pelvic bones of ovariectomized rats that showed osteoporosis signs for the first time. In this study, 20 Rattus norvegicus were given ovariectomy at 12 weeks of age and were used as an animal model for menopausal women. The rats were euthanized every 2 weeks from 13 to 21 weeks of age. In addition, the pelvic bones of ovariectomized rats will be analyzed using FTIR and Raman spectroscopy to show the first osteoporosis signs periodically. Results of FTIR and Raman spectroscopy indicated that the pelvic bones of the ovariectomized rats showed the first osteoporosis signs at 17 weeks of age with changes in phosphate and carbonate contents, increased hydroxyl functional groups, reduction of mineral maturity about 7.47%, and reduction of crystallinity about 29.26%. In addition, morphological changes from fine fibers to coarser fibers and reduction of the crystal size and crystallinity index at the angle of 2θ ≅ 25° about 9.29% and 25.18%, respectively, were observed using SEM-EDS and XRD.

Synergistic Effect of Sesamin and γ-Tocotrienol on Promoting Osteoblast Differentiation via AMPK Signaling

Background: Sesamin is a rich phytochemical found in sesame seed oil that can promote osteoblast differentiation of rat BMSCs and improve rat bone structure by regulating Wnt/-Catenin pathway. Combined sesamin and γ-Tocotrienol (γ-T3) have been clarified to inhibit the proliferation of breast cancer cells, but their role in osteoporosis has not been explored. This paper aimed to discuss the synergistic effect of sesamin and γ-T3 in osteoporosis and disclose the underlying mechanism. Materials and methods: CCK-8 assay was to appraise the proliferation of hBMSCs after treated with sesamin and γ-T3. Moreover, the proteins in AMPK signaling in osteoblasts pretreated with AMPK inhibitor compound C (CC) were detected after the induction of sesamin and γ-T3. Then, CCK-8, ALP assay and ARS staining were used to analyze whether the proliferation and osteoblast differentiation of hBMSCs was via APMK pathway. RT-qPCR and western blot were conducted to quantify the levels of markers in osteoblasts. Results: It was determined that 5 g/mL sesamin and 1 μM γ-T3 exerted obvious influences on the viability of hBMSCs. Moreover, the co-treatment of sesamin and γ-T3 elevated the protein levels of related factors in AMPK pathway, which was reversed by CC. Furthermore, The proliferation and osteoblast differentiation exhibited remarkable increments upon exposure to both sesamin and γ-T3, whereas CC abolished these effects. Conclusion: In conclusion, the present study presented the first line of evidence to verify the synergystic effects of sesamin and γ-T3 on alleviating osteoporosis, and revealed their effects were realized by modulating the AMPK pathway. This paper has indicated the great potential of combined sesamin and γ-T3 in osteoporosis treatment.

Improving the repair mechanism and miRNA expression profile of tibial defect in rats based on silent information regulator 7 protein analysis of mesenchymal stem cells

ABSTRACT The aim of this study was to verify the role of Silent Information Regulator 7 (SIRT7) in improving the repair mechanism of bone marrow mesenchymal stem cells (BMMSCs) and the expression of microribonucleic acid (miRNA). Human BMMSCs were extracted from patients with femoral fractures, and the proliferation activity of human BMMSCs before and after knockout SIRT7 and the expression levels of bone-related genes and proteins were compared. Thirty-two 8-week-old male Sprague-Dawley (SD) rats were randomly divided into a blank group, a chitosan scaffold group, a control group, and a silence information regulator knockout group 7 (n = 8). In addition to the blank group, the chitosan scaffold, the green fluorescent protein (GFP) transfected stem cell composite chitosan scaffold, and the SIRT7 knockout stem cell composite chitosan scaffold were implanted in the other three groups, respectively. The X-rays and small animal in vivo three-dimensional tomography (Micro-CT) were adopted to quantitatively analyze the volume fraction, the number of trabeculae, and the connection density. Compared with the other three groups, the bone defect was formed more in the medullary mesenchymal stem cell knockout group, and the bone volume fraction, number of trabeculae and connection density were significantly increased (P < 0.05). MiR-98-5p can significantly promote the formation of bone molecules and bone structure in rats (P < 0.05). Human BMMSCs combined with chitosan scaffold can accelerate the repair of tibial defects. MiR-98-5p targeting and regulating bone formation gene (CKIP-1) could significantly improve the process of osteogenesis in rats.

Effects of Zoledronic Acid on Bone Structure and Organization of Nanocomposites in Rats with Glucocorticoid-Induced Osteoporosis

Continuous use of methylprednisolone (Mps) is one of the most common causes of secondary osteoporosis resulting in alterations of the skeleton microstructure and increased fracture risk. The aim of the research was to assess the influence of zoledronic acid on mineral mass, micro- and nanostructure of the bones in rats, which received glucocorticoids. Wistar rats were randomly divided into three groups: vehicle control, the introduction of methylprednisolone, 3 mg/kg/day (Mps), and Mps combined with zoledronic acid, 0.025 mg/kg (Mps+Zol.). The relative amount of a crystalline component and collagen in the bones was detected by means of X-ray diffraction, microstructure, and calcium level through atomic absorption spectroscopy. Methylprednisolone caused a decrease in the amount of a mineral component in the femoral neck (to -39.8%) in group Mps than vehicle control. It should be emphasized that the introduction of Zol. did not allow a significant decrease in a mineral component of the bone during the experiment (-11.7% on the 24th day) compared with Mps group, and indices were almost at the same level as in the control group. Zoledronic acid can partially inhibit harmful consequences of glucocorticoids for bone structure in rats and improve mineralization without impairment of crystal parameters of hydroxyapatite lattice.

Dose-Dependent Impact of Bee Pollen Supplementation on Macroscopic and Microscopic Structure of Femoral Bone in Rats.

Simple SummaryBee pollen is considered an interesting feed supplement with beneficial health impacts. It contains many basic nutritional compounds that improve growth performance, development and immune response of animals. However, its effect on bone structure has been studied to a limited extent and the results published so far are ambiguous. Therefore, the impact of bee pollen supplementation on selected bone characteristics of rats was investigated in our study. We determined a dose-dependent effect of bee pollen administration on macroscopic and microscopic structure of femoral bone. Several negative effects of bee pollen supplementation at the level of 0.75% on bone features have been demonstrated, while the level of 0.5% did not influence these properties in rats.Bee pollen has been successfully used as a feed additive with beneficial impacts on productive, reproductive, and immune conditions of animals. However, its effect on bone structure and bone health remains controversial. Therefore, the purpose of our study was to examine the impact of bee pollen supplementation on macroscopic and microscopic structure of a femoral bone using rats as suitable animal models. Male rats (1 month-old) were assigned into three groups: control (C group) that was fed a standard diet without bee pollen and two bee pollen supplemented groups (P1 and P2 groups) that received an experimental diet including 0.5% and 0.75% of bee pollen, respectively, for 3 months. A number of unfavorable effects of 0.75% bee pollen administration on bone weight, cortical bone thickness, calcium content, alkaline phosphatase activity, sizes of primary osteons’ vascular canals, Haversian canals and secondary osteons in the cortical bone have been recorded, whereas these bone parameters were significantly decreased in the P2 group versus the C group. On the contrary, the concentration of 0.5% did not affect any of bone features mentioned above. In conclusion, the impact of bee pollen supplementation on femoral bone structure of rats depends on the dose used.

Effects of mechanical stimuli on structure and organization of bone nanocomposites in rats with glucocorticoid-induced osteoporosis.

Objective. Clinical use of glucocorticoids is a frequent cause of secondary osteoporosis, which reduces the mineral density of bones and results in pathological fractures. Mechanical stimulation as non-physiological high-frequency vibration with low acceleration prevents the loss of a crystalline component and stimulates the anabolic remodeling of the bone. The aim of the present research was to assess the impact of mechanical vibration on the bone structure in rats, which received glucocorticoids.Methods. Wistar rats were randomized into three groups: Vehicle control (Veh), Methylprednisolone sodium succinate (Mps), and Mps combined with whole-body vibration (WBV). Rats of Mps+WBV and Mps groups received 3 mg/kg/day of methylprednisolone every other day for 24 weeks and rats of Veh group received 0.9% saline (sodium chloride). The group of rats Mps+WBV was subjected to WBV for 30 minutes per day for five days a week with parameters 0.3 g and frequency 50 Hz. Relative amount of crystalline component and collagen in the bones was determined by X-ray diffraction (XRD) and calcium level - by atomic absorption spectroscopy. Bone tissue metabolism was assessed by determining the concentration of markers, in particular osteocalcin and Tartrate-resistant acid phosphatase (TRAP5b).Results. Glucocorticoids induced a considerable increase in the rats body mass (+13%) and decreased the content of mineral component in the femoral neck (-17%) in Mps group compared with Veh. The process of the bone metabolism was significantly accelerated, which is proven by an increased level of remodeling markers. It should be mentioned that WBV did not allow significant decrease in mineral component of the bone to 16th week of the experiment compared with Mps group, although these parameters did not achieve the indices in the Vehicle control group (-10%). Our investigation allows to suggest that mechanical high-frequency vibration of low intensity can partially inhibit the harmful consequences of glucocorticoids on bone structure in rats. Despite the positive impact of vibration on the bone tissue after Mps introduction in the 8th-16th week, this influence was not statistically reliable in the 24th week of the experiment.Conclusions. The results of our investigation on animal model indicate that non-physiological vertical mechanical vibrations are an effective means to prevent loss of a mineral bone component during treatment with glucocorticoids.

Bone protective effects of purified extract from Ruscus aculeatus on ovariectomy-induced osteoporosis in rats

Ruscus aculeatus is a source of steroidal saponins that could mimic sex hormones and could help alleviate the risk of fracture in osteoporotic patients. The aim of the present study was to evaluate the in vitro effects of an extract from R. aculeatus (ERA) on the proliferation of human osteoblast-like SaOS-2 cell line and to investigate the effects of the ERA administered orally for 10 weeks at three doses (50, 100 and 200 mg/kg) on the bone structure of rats with estrogen deficiency induced by bilateral ovariectomy. Bone turnover markers, hormones, histopathological and radiological disturbances were evidenced in the ovariectomized rats. ERA recovered most of the affected parameters in a dose-dependent manner similar to diosgenin and alendronate used as positive comparators. The main active compounds of ERA (ruscogenin and neoruscogenin) were docked into the Vit. D receptor and oestrogen receptors alpha and beta, and stable complexes were found with binding scores equal to those of estradiol and diosgenin.The findings of this study provide for the first time an insight into the effects of ERA on bone structure and suggest that ERA could be developed as a potential candidate for the prevention of postmenopausal osteoporotic complications.

Treatment with hydrogen sulfide donor attenuates bone loss induced by modeled microgravity

The present study was undertaken to explore the therapeutic potential of hydrogen sulfide against bone loss induced by modeled microgravity. Hindlimb suspension (HLS) and rotary wall vessel bioreactor were applied to model microgravity in vivo and in vitro, respectively. Treatment of rats with GYY4137 (a water soluble donor of hydrogen sulfide, 25 mg/kg per day, i.p.) attenuated HLS-induced reduction of bone mineral density in tibiae, and preserved bone structure in tibiae and mechanical strength in femurs. In HLS group, GYY4137 treatment significantly increased levels of osteocalcin in sera. Interestingly, treatment of HLS rats with GYY4137 enhanced osteoblast surface, but had no significant effect on osteoclast surface of proximal tibiae. In MC3T3-E1 cells exposed to modeled microgravity, GYY4137 stimulated transcriptional levels of runt-related transcription factor 2 and enhanced osteoblastic differentiation, as evidenced by increased mRNA expression and activity of alkaline phosphatase. HLS in rats led to enhanced levels of interleukin 6 in sera, skeletal muscle, and tibiae, which could be attenuated by GYY4137 treatment. Our study showed that GYY4137 preserved bone structure in rats exposed to HLS and promoted osteoblastic differentiation in MC3T3-E1 cells under modeled microgravity.

Effect of fish oil supplementation on alveolar bone structure in rats with glucocorticoid induced osteoporosis (Histological, immunohistochemical & ultrastructural study)

Glucocorticoids are widely used in treatment of many medical disorders. However, many side effects are associated with the chronic use of glucocorticoids administration especially osteoporosis. Fish oil contains omega 3 polyunsaturated fatty acids which can inhibit the production of inflammatory mediators such as IL-6 and TNF-α which are important for osteoclastogenesis. So the aim of the present work was to test the efficiency of fish oil administration on alveolar bone osteoporosis induced by glucocorticoid administration. Materials & methods: 8 Wistar albino rats were divided into 3 groups. Group Ι: control group. Group ΙΙ (osteoporotic group): rats were given 7 mg/kg of dexamethasone, once a week intramuscularly for 5 weeks. Group ΙΙΙ (fish oil treated group): rats were given the same dose of dexamethasone like group ΙΙ and at the same time were given daily an oral dose of fish oil 1gm/kg/day. All rats were sacrificed after 5 weeks from the start of the experiment and molar segments of the jaw were dissected out. They were examined histologically, immunohistochemically, histomorphometrically and ultrastructurally. Results: Histologically in osteoporotic group ΙΙ the bone showed marked resorption with the presence of many osteoclasts which showed significant increase in number and intense TRAP immunostaining. By scanning electron microscope the buccal cortical plate showed obvious erosion. On the other hand, fish oil treated group showed marked improvement where the bone appeared denser with significant decrease in osteoclast number which exhibited mild TRAP staining. Histomorphometriclly, the bone surface area showed marked increase. Ultrastructurally, the bone surface appeared relatively smooth. Conclusions: fish oil supplementation could to a large extent overcome the detrimental effect of glucocorticoid administration on the structure of the alveolar bone.

Oral administration of kaempferol inhibits bone loss in rat model of ovariectomy-induced osteopenia.

Postmenopausal osteoporosis and osteoporotic fractures constitute an increasing problem in developing countries. Kaempferol, isolated from seeds of Cuscuta chinensis, is an active flavonoid inhibiting in vitro osteoclast activity. The aim of the presented research was an assessment of kaempferol effect on estrogen-deficiency-induced bone structure disturbances in rats. The study was performed on 24 Wistar female rats divided into 3 groups: SHAM - rats undergoing a "sham" surgery, OVX-C - control group of animals that underwent ovariectomy, OVX-K - rats undergoing ovariectomy and receiving kaempferol for 8 weeks (from day 56 to day 112). In the OVX-K group, contrary to the OVX-C one, there was no significant decrease in femoral bone mineral density (BMD). A significant increase in Young's modulus was observed in the OVX-K group compared to the OVX-C (15.33±2.51GPa vs. 11.14±1.93GPa, p<0.05). A decreased bone turnover was detected in the OVX-K group. Tissue volume ratio (BV/TV) and trabecular bone perimeter were increased in the OVX-K group compared to the OVX-C one (0.241±0.037 vs. 0.170±0.022, p<0.05 and 15.52±2.78mm vs. 9.67±3.07mm, p<0.05, respectively). Kaempferol has a beneficial influence on estrogen-deficiency-induced disturbances of bone structure in rats.

Nitrogen-containing bisphosphonate therapy: assessment of the alveolar bone structure in rats - a blind randomized controlled trial.

This study aimed to assess the effect of zoledronic acid exposure on structures of the alveolar bone of rats. The sample was composed of 42 male Wistar rats. Animals in the T1 and T2 groups received weekly doses of 0.2 mg/kg intraperitoneal zoledronic acid for 3 weeks, while animals in the T3 group received the same treatment for 8 weeks. The control groups C1, C2 and C3 received equivalent doses of saline. The first upper molars of Wistar rats in the C2, T2, C3 and T3 groups were extracted. Cone-beam computerized tomography scans were performed, and the image density was analysed by grey levels. The presence and type of inflammatory infiltrate, vascularization and bone necrosis were assigned by histological qualitative scores. Histomorphometric analysis of bone density was performed in the groups without extraction. No significant differences were found in the bone grey density estimated by grey-level value and histomorphometric analysis between the C1 and T1 groups (P > 0.05). The grey levels in the T3 group were lower (P < 0.05) than in the C3 group, corresponding to the bone defect. Histological assessments showed the presence of bone necrosis in the T3 group and lower levels of bone remodelling in the test groups (T2 and T3) compared to the control groups (C2 and C3). The results of qualitative analyses did not differ significantly between the groups (P > 0.05). Zoledronic acid-exposed animals showed maxillary changes including reduced grey levels, the presence of bone necrosis and a higher prevalence of inflammatory signs.

Changes of trabecular bone structure in rats with sciatic nerve denervation

Changes of trabecular bone structure in rats with sciatic nerve denervation

Mechanical vibration preserves bone structure in rats treated with glucocorticoids

Glucocorticoids are an important cause of secondary osteoporosis in humans, which decreases bone quality and leads to fractures. Mechanical stimulation in the form of low-intensity and high-frequency vibration seems to be able to prevent bone loss and to stimulate bone formation. The objective of this study was to evaluate the effects of mechanical vibration on bone structure in rats treated with glucocorticoids. Thirty 3-month-old adult male Wistar rats were randomized to three groups: control (C), glucocorticoid (G), and glucocorticoid with vibration (GV). The G and GV groups received 3.5 mg/kg/day of methylprednisolone 5 days/week for a duration of 9 weeks, and the C group received vehicle (saline solution) during the same period. The GV group was vibrated on a special platform for 30 min per day, 5 days per week during the experiment. The platform was set to provide a vertical acceleration of 1 G and a frequency of 60 Hz. Skeletal bone mass was evaluated by total body densitometry (DXA). Fracture load threshold, undecalcified bone histomorphometry, and bone volume were measured in tibias. Glucocorticoids induced a significantly lower weight gain (− 9.7%) and reduced the bone mineral content (− 9.2%) and trabecular number (− 41.8%) and increased the trabecular spacing (+ 98.0%) in the G group, when compared to the control (C). Vibration (GV) was able to significantly preserve (29.2%) of the trabecular number and decrease the trabecular spacing (+ 26.6%) compared to the G group, although these parameters did not reach C group values. The fracture load threshold was not different between groups, but vibration significantly augmented the bone volume of the tibia by 21.4% in the GV group compared to the C group. Our study demonstrated that low-intensity and high-frequency mechanical vibration was able to partially inhibit the deleterious consequences of glucocorticoids on bone structure in rats.

The visualization and evaluation of bone architecture in the rat using three-dimensional X-ray microcomputed tomography.

Microcomputed tomography allows the true three-dimensional structure of bone to be assessed by a nondestructive analysis. This article describes how this technique has for the first time been applied to rat bone to determine the effects of aging, ovariectomy, and antiresorptive drugs on bone structure and how these results compare with those determined by histological and histomorphometric techniques. During the procedure, a micro X-ray source is directed toward the bone sample. Modifications in the X-ray beam induced by bone crystals are determined for a range of acquisitions before three-dimensional reconstruction of bone architecture is performed. Morphometric parameters determined were trabecular bone volume/tissue volume, trabecular number, and trabecular thickness. The results show that ovariectomy has a dramatic effect on rat bone structure. Following treatment with the bone resorption inhibitor tiludronate, the morphometric parameters were significantly improved. The results obtained with three-dimensional microcomputed tomography were in agreement with observations made using classical techniques. Microcomputed tomography should prove useful for evaluating the antiresorptive effects of bisphosphonates on bone architecture and in allowing between-drug comparisons.