ai_agent

This work is supported by grants from (1) National Nature Science Foundation (82305275). (2) Liaoning Provincial Natural Science Foundation program (2022-YGJC-80 and 2022-YGJC-79). (3) High-level Chinese Medicine Key Discipline Construction Project of National Administration of TCM (zyyzdxk-2023040).

Female Sprague Dawley rats (n = 36), aged 12 weeks and weighing approximately 200-240 g, were housed individually in ventilated cages in a specific-pathogen-free (SPF) animal room with a 12-h light/dark cycle. They had free access to SPF feed and sterile water. The rats were allowed to acclimate to the environment for a week before the experiments. Using random allocation, the rats were divided into ovariectomized (OVX) groups (each with 6 rats) and sham groups (each with 6 rats) for 4, 8, and 12 weeks post-surgery. All animal procedures were carried out following the approved guidelines of the animal welfare committee at Liaoning University of Traditional Chinese Medicine (No. 21000042021040).
1. Ovariectomy in rats
NOTE: The surgical apparatus used in this protocol is in Figure 1.
<ol>
	<li>Keep the rats in the SPF animal room and follow all necessary procedures using sterilized equipment in a sterile environment.</li>
	<li>Administer the analgesic drug Tramadol Hydrochloride at a dose of 10 mg/kg (200&#160;&#181;L from 0.1mg/mL) via subcutaneous injection 30 min before surgery. Use 5% isoflurane dissolved in 2 L/min of oxygen for inhalation anaesthesia.</li>
	<li>Following the administration of anesthesia, carefully monitor the rat&#39;s breathing and pinch their toes to confirm the surgical plane of anesthesia. 
	NOTE: If there are any signs of spasms or convulsions, it is advisable to wait longer before proceeding.</li>
	<li>Position the rat on a resin workbench and provided a heating support.&#160;Secure its limbs, and remove the hair on both sides of its back using a trimmer&#160;ensuring that 150% of the area surrounding the surgical site is free of fur, and then drape the animal (Figure 2A). 
	NOTE: If the hair removal effect is not ideal, hair removal cream can be used for hair removal.</li>
	<li>Disinfect the area where the hair was removed using cotton balls soaked in both an iodine-based and alcohol. 
	NOTE: The process of surgical disinfection involves starting from the center and moving outwards in a circular pattern, typically repeated three times.</li>
	<li>Make an incision on the back, about 1.0 cm away from the centerline. Make the incision close to the juncture between the rib cage curvature and the border of the spinal column, slightly lower by 0.5-1 cm by separating the skin, fascia, and muscle on both sides (Figure 2B). 
	NOTE: For accessing the abdominal cavity through the weaker muscle layer of the posterior abdominal wall, the incision is kept as minimal as feasible.</li>
	<li>Finding the ovary can be challenging at first. Start by locating the oviduct and tracing it to the ovary&#39;s terminal end, which is encased in a layer of loose adipose tissue. 
	NOTE: The right ovary is positioned on the side of the 4th to 5th lumbar vertebrae, 7-12 mm behind the kidney and 15 mm away from the center line. The left ovary is situated on the side of the 5th to 6th lumbar vertebrae, 3-5 mm behind the kidney and 11 mm from the center line.</li>
	<li>Carefully lift the ovary and the end of the oviduct out of the body (Figure 2C). Apply the hemostatic forceps at the most constricted region between the uterine end and the ovary. Use a surgical thread to tie it off, and then excise the ovary completely with scissors. 
	NOTE: It is crucial to be gentle when handling the oviduct and the uterus during the procedure, avoiding excessive pulling. The ligature used prior to ovariectomy must be firmly secured, as the soft lipid tissue around the ovary can easily cause it to come loose. This precaution is necessary to prevent postoperative bleeding, which could result in the rats&#39; death. In the sham group, adipose tissue of equal volume and size adjacent to the ovary was excised, followed by suturing of the muscle and skin.</li>
	<li>Release the hemostatic forceps and gently return the uterus to the abdominal cavity.</li>
	<li>Individually suture the skin and muscle layers using 5-0 absorbable surgical sutures made of polyethylene glycol (Figure 2D).</li>
	<li>Place the rat back in a sanitized cage and monitor it until it completely regains consciousness from the anesthesia. 
	NOTE: Continue to provide heat support during the procedure until the animal has fully recovered from anesthesia.</li>
	<li>Within 48 h postoperatively, administer Ketorolac Tromethamine at a dose of 1&#8211;2 mg/kg via subcutaneous injection twice a day.</li>
	<li>To avoid wound infection, administer the rats in each group with an intramuscular injection of penicillin sodium 80,000 units/rat once a day for 3 consecutive days26.</li>
</ol>
2. Collection of bone tissue and muscle tissues
NOTE: Rats were euthanized with an overdose of sodium pentobarbital (100-200 mg/kg) at 4, 8, and 12 weeks after the modeling surgery. A total of 36 samples were collected.
<ol>
	<li>Expose the triceps brachii and quadriceps muscles of the left calf. Carefully identify and dissect these muscles at their points of origin and endpoint to preserve their integrity. Following this, record and calculate the average of the wet weights of the muscles to determine the wet weight coefficients of the muscles. 
	NOTE: Animal body weight and skeletal muscle wet weight coefficient = rat muscle wet weight/body weight.</li>
	<li>Fully detach the femur by slicing the joint capsule upwards along the femur. Then, eliminate the nearby muscle and ligament tissue.</li>
</ol>
3. Pathological examination
<ol>
	<li>Immerse the muscle tissues in a receptacle containing a 10% neutral buffered formalin solution for a duration of 24 h. Following this, rinse the muscle tissues extensively under flowing water to remove the fixative.</li>
	<li>Place the left femur in a 4% paraformaldehyde solution for 1 week, then soak it in a sufficient amount of ethylenediaminetetraacetic acid (EDTA) decalcification solution to remove calcium deposits, with the buffer being changed daily.</li>
	<li>Measure the bone mineral density values using a dual-energy X-ray absorptiometry (DXA) bone densitometer. Place the femur in a dual-energy X-ray. Set the measurement accuracy to Fine, adjusting the mode to Small Animal-Specific Mode, and analyze the BMD of rat femurs using the accompanying BMD analysis software.</li>
	<li>Place the sample in paraffin wax. Section the samples for the routine histological examination27.</li>
</ol>
4. Statistical analysis
<ol>
	<li>Present the continuous variables as mean &#177;&#177; standard deviation (SD) and compare between the two groups using the independent sample t-test. All statistical analyses followed a two-sided approach, with statistical significance set at P &#60; 0.05. Use appropriate data analysis software to perform data analyses.</li>
</ol>

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</ol>

Each author declares no competing financial interests.

The bilateral ovariectomized animal model is instrumental in elucidating the mechanisms underlying osteosarcopenia and assessing potential therapeutic interventions. Ovariectomy-induced osteoporosis in rats, which mirrors the abrupt decrease in estrogen levels seen in postmenopausal women, is commonly employed as a model for osteoporosis research. Furthermore, research has highlighted a significant association between osteoporosis and sarcopenia in older individuals, with concurrent muscle and bone loss frequently observ...

Osteosarcopenia is a multifaceted degenerative condition that encapsulates the clinical manifestations of both osteoporosis and sarcopenia1,2,3,4. Osteoporosis, a prevalent skeletal disorder, is characterized by diminished bone mass, compromised microarchitecture, and heightened susceptibility to fractures. Sarcopenia, often referred to as muscle wasting syndrome, is typified by a reduction in muscle strength and mass5,6. Maryam&#39;s7 findings revealed that osteosarcopenia increased the risk of death by 30% over sarcopenia alone and by 8% over low BMD alone. Research has shown that 16.4% of community-dwelling individuals aged 60 and above are affected by osteosarcopenia8. In South Korea, the incidence of osteosarcopenia among elderly individuals aged 60 and above who have sustained hip fractures is reported to be 27.2%9. Individuals with OS face higher risks of falls, fractures, hospitalization, and institutionalization, which burdens the healthcare system and society10,11. Given the gravity of these consequences, it is crucial to develop and implement efficient measures for the prevention and treatment of OS. Despite the urgency, research in this field remains nascent, with ongoing debates surrounding diagnostic criteria and the efficacy of various treatment modalities. The development of reliable animal models is thus essential for dissecting the pathogenesis of OS and uncovering the molecular underpinnings that could inform more efficacious treatment approaches.
Currently, commonly used models for preclinical studies on osteosarcopenia include the aging model, which simulates the human aging process without drug intervention. This approach is closer to the natural process and is cost-effective; however, it demands a significant investment of time for maturation12. The chemical drug injection method offers certain benefits, such as a short modeling cycle, stable results, and low cost. However, it also presents challenges, including the precise determination of hormone dosage, the technical skill required for injection, and the variable effects of hormonal interventions13,14. Genetic engineering models may involve genetically modified organisms that can be both genetically defective and costly. Although these models are highly specific, they are notably more complex and expensive to produce15. Disuse models simulate the effects of prolonged bed rest on clinical patients16. Disuse models are effective and cost-efficient for addressing muscle loss but are associated with complications such as blood clots and pressure sores. These models are routinely monitored to prevent limb necrosis17,18 and hormone-deficient models; there is a prevailing agreement within the scientific community that bilateral ovariectomy serves as an effective method for establishing an animal model of osteoporosis19,20.
Research indicates that bone and muscle tissues can also interact with each other through autocrine, endocrine, and paracrine mechanisms21. The accumulation of adipose tissue in muscle and bone marrow serves as an indicator of reduced bone and muscle mass in the context of osteosarcopenia2. Sarcopenia in older adults is directly associated with a reduction in bone density and the deterioration of bone microarchitecture. Additionally, diminished muscle mass serves as an independent risk factor for the degradation of bone microstructure22. This methodology has been recognized as a viable strategy for the modeling of sarcopenia23,24, which could potentially serve as a combined model for both conditions25. Despite the limited body of research concerning the application of ovariectomy as a means to induce osteosarcopenia, this approach demonstrates potential efficacy. The benefits of utilizing ovariectomy in preclinical studies encompass a swift modeling process, the elimination of pharmacological interventions, the creation of a stable experimental model, straightforward implementation, and cost-effectiveness.
The present study aims to delineate the procedure for creating a preclinical model in female rats through the removal of a segment of both fallopian tubes and ovaries in non-pregnant individuals. This approach serves as a valuable tool for investigating the molecular underpinnings of OS and for assessing the therapeutic benefits of interventions in a controlled experimental setting.

<table><tbody><tr><td>Double lion Irradiated Rodent Diet</td><td>Suzhou Shuangshi Experimental Animal Feed Technology Co., Ltd.</td><td>GB 14924.3</td><td>Animal feed</td></tr><tr><td>Disposable medication changing tray</td><td>Yangzhou Chenglin Medical Technology Co., Ltd.</td><td>RVnpFXLc</td><td></td></tr><tr><td>Dual Energy X-ray Bone Densitometer</td><td>Xuzhou PinyuanElectronic Technology Co., Ltd.</td><td>DXA-800E</td><td></td></tr><tr><td>Iodine</td><td>Shanghai Likang Sterilization Hi-Tech Co., Ltd.</td><td>LK-310512</td><td></td></tr><tr><td>IVCs rat cage</td><td>Suzhou Monkey King Animal Experimental Equipment Technology Co., Ltd.</td><td>HH-MMB-2</td><td>Animal barrier</td></tr><tr><td>Ketorolac tromethamine Injection</td><td>Yunnan Longhai Natural Plant Medicine Co., Ltd.</td><td>H20233312</td><td></td></tr><tr><td>Penicillin sodium</td><td>North China Pharmaceutical Group Limited Liability&amp;nbsp; Co., Ltd.</td><td>H13020654</td><td></td></tr><tr><td>Sterile cotton ball</td><td>Henan Piaoan Group Co., Ltd</td><td>20140017</td><td></td></tr><tr><td>Straight Mayo scissors</td><td>Shenzhen Huayang Biotechnology Co., Ltd.</td><td>18-0410</td><td></td></tr><tr><td>Straight needle holder</td><td>Shanghai Simplicity Biotechnology Co., Ltd.</td><td>32100-14</td><td></td></tr><tr><td>Suture line</td><td>Shenzhen Huayang Biotechnology Co., Ltd.</td><td>18-5902</td><td></td></tr><tr><td>Suture needle</td><td>Shenzhen Huayang Biotechnology Co., Ltd.</td><td>18-5036</td><td></td></tr><tr><td>Syringes</td><td>Shenzhen Huayang Biotechnology Co., Ltd.</td><td>21-3021</td><td></td></tr><tr><td>Tramadol hydrochloride</td><td>Grunenthal GmbH</td><td>H20140812</td><td></td></tr></tbody></table>

the creation of a rat model for osteosarcopenia via ovariectomy

Osteosarcopenia (OS), a complex degenerative disorder, is characterized by the concurrent decline in skeletal muscle mass and bone mineral density (BMD), posing an enormous health hazard for the elderly population. Despite its clinical relevance, the pathophysiological mechanisms underlying OS are not fully understood, underscoring the necessity for a deeper comprehension of its etiology to facilitate effective treatment strategies. The development of a reliable animal model is pivotal in this endeavor. This study presents a refined protocol for the induction of postmenopausal osteosarcopenia in rats through bilateral ovariectomy, a method known to accelerate the onset of age-related muscle and bone loss. In this study, rats aged 12 weeks were stratified by body weight and randomly assigned to either a sham operation group or an ovariectomized (OVX) group. Tissue samples from the quadriceps and triceps muscles of the left hind limb, as well as the left femur, were systematically collected at 4, 8, and 12 weeks post-surgery. This methodical approach ensures a comprehensive evaluation of the effects of ovariectomy on muscle and bone health. Histological evaluation of muscle fiber atrophy and femoral morphology was conducted using hematoxylin and eosin (HE) staining, while bone mineral density was quantified using dual-energy X-ray absorptiometry (DXA). The temporal progression of OS was meticulously monitored at the aforementioned intervals, providing insights into the dynamic interplay between muscle and bone degeneration. This model not only accurately reflects the clinical manifestations of OS but also serves as a robust platform for investigating novel therapeutic approaches and their underlying mechanisms.

This protocol provides a detailed description of the bilateral ovariectomy procedure for establishing a rat model of Osteosarcopenia. Figure 3 demonstrates a decrease in the wet weight coefficient of the quadriceps muscle in the OVX group in comparison to the sham group. Although there was no statistically significant variance in BMD between the two groups 4 weeks after surgery, the BMD in the OVX group was significantly lower than that in the sham-operated g...

This current protocol outlines a procedure for creating a rat model of osteosarcopenia using ovariectomy.

The Creation of a Rat Model for Osteosarcopenia via Ovariectomy

Osteosarcopenia (OS), a complex degenerative disorder, is characterized by the concurrent decline in skeletal muscle mass and bone mineral density (BMD), ...

the-creation-of-a-rat-model-for-osteosarcopenia-via-ovariectomy

Research

JoVE Journal

Medicine

693 Views.  The Affiliated Hospital of Liaoning University of Traditional Chinese Medicine. This current protocol outlines a procedure for creating a rat model of osteosarcopenia using ovariectomy.

Video: The Creation of a Rat Model for Osteosarcopenia via Ovariectomy

Ovariectomy and 17&beta;-estradiol Replacement in Rats and Mice: A Visual Demonstration

Estrogens are a family of female sexual hormones with an exceptionally wide spectrum of effects. When rats and mice are used in estrogen research they are commonly ovariectomized in order to ablate the rapidly cycling hormone production, replacing the 17&beta;-estradiol exogenously. There is, however, lack of consensus regarding how the hormone should be administered to obtain physiological serum concentrations. This is crucial since the 17&beta;-estradiol level/administration method profoundly influences the experimental results1-3. We have in a series of studies characterized the different modes of 17&beta;-estradiol administration, finding that subcutaneous silastic capsules and per-oral nut-cream Nutella are superior to commercially available slow-release pellets (produced by the company Innovative Research of America) and daily injections in terms of producing physiological serum concentrations of 17&beta;-estradiol4-6. Amongst the advantages of the nut-cream method, that previously has been used for buprenorphine administration7, is that when used for estrogen administration it resembles peroral hormone replacement therapy and is non-invasive. The subcutaneous silastic capsules are convenient and produce the most stable serum concentrations. This video article contains step-by-step demonstrations of ovariectomy and 17&beta;-estradiol hormone replacement by silastic capsules and peroral Nutella in rats and mice, followed by a discussion of important aspects of the administration procedures.

Ovariectomy and 17&#946;-estradiol Replacement in Rats and Mice: A Visual Demonstration

Ovariectomy and subsequent replacement of 17&beta;-estradiol by means of silastic capsules and peroral Nutella are demonstrated in rats and mice.

Estrogens are a family of female sexual hormones with an exceptionally wide spectrum of effects. When rats and mice are used in estrogen research they are ...

Biology

A Novel in vivo Gene Transfer Technique and in vitro Cell Based Assays for the Study of Bone Loss in Musculoskeletal Disorders

Differentiation and activation of osteoclasts play a key role in the development of musculoskeletal diseases as these cells are primarily involved in bone resorption. Osteoclasts can be generated in vitro from monocyte/macrophage precursor cells in the presence of certain cytokines, which promote survival and differentiation. Here, both in vivo and in vitro techniques are demonstrated, which allow scientists to study different cytokine contributions towards osteoclast differentiation, signaling, and activation. The minicircle DNA delivery gene transfer system provides an alternative method to establish an osteoporosis-related model is particularly useful to study the efficacy of various pharmacological inhibitors in vivo. Similarly, in vitro culturing protocols for producing osteoclasts from human precursor cells in the presence of specific cytokines enables scientists to study osteoclastogenesis in human cells for translational applications. Combined, these techniques have the potential to accelerate drug discovery efforts for osteoclast-specific targeted therapeutics, which may benefit millions of osteoporosis and arthritis patients worldwide.

A Novel in vivo Gene Transfer Technique and in vitro Cell Based Assays for the Study of Bone Loss in Musculoskeletal Disorders

Differentiation of precursor cells into osteoclasts is regulated by cytokines and growth factors. Here, a novel gene transfer technique for differentiation of osteoclasts in vivo and cell culture protocols for differentiating precursor cells into osteoclasts in vitro as a method to study the effects of cytokines on osteoclastogenesis are described.

Differentiation and activation of osteoclasts play a key role in the development of musculoskeletal diseases as these cells are primarily involved in bone ...

Semiautomated Longitudinal Microcomputed Tomography-based Quantitative Structural Analysis of a Nude Rat Osteoporosis-related Vertebral Fracture Model

Osteoporosis-related vertebral compression fractures (OVCFs) are a common and clinically unmet need with increasing prevalence as the world population ages. Animal OVCF models are essential to the preclinical development of translational tissue engineering strategies. While a number of models currently exist, this protocol describes an optimized method for inducing multiple highly reproducible vertebral defects in a single nude rat. A novel longitudinal semiautomated microcomputed tomography (&#181;CT)-based quantitative structural analysis of the vertebral defects is also detailed. Briefly, rats were imaged at multiple time points post-op. The day 1 scan was reoriented to a standard position, and a standard volume of interest was defined. Subsequent &#181;CT scans of each rat were automatically registered to the day 1 scan so the same volume of interest was then analyzed to assess for new bone formation. This versatile approach can be adapted to a variety of other models where longitudinal imaging-based analysis could benefit from precise 3D semiautomated alignment. Taken together, this protocol describes a readily quantifiable and easily reproducible system for osteoporosis and bone research. The suggested protocol takes 4 months to induce osteoporosis in nude ovariectomized rats and between 2.7 and 4 h to generate, image, and analyze two vertebral defects, depending on tissue size and equipment.

The goal of this protocol is to generate a nude rat osteoporosis-related vertebral compression fracture model that can be longitudinally evaluated in vivo using a semiautomated microcomputed tomography-based quantitative structural analysis.

Osteoporosis-related vertebral compression fractures (OVCFs) are a common and clinically unmet need with increasing prevalence as the world population ...

Bioengineering

A Syngeneic Orthotopic Osteosarcoma Sprague Dawley Rat Model with Amputation to Control Metastasis Rate

The most recent advance in the treatment of osteosarcoma (OS) occurred in the 1980s when multi-agent chemotherapy was shown to improve overall survival compared to surgery alone. To address this problem, the aim of the study is to refine a lesser-known model of OS in rats with a comprehensive histologic, imaging, biologic, implantation, and amputation surgical approach that prolongs survival. We used an immunocompetent, outbred Sprague-Dawley (SD), syngeneic rat model with implanted UMR106 OS cell line (originating from a SD rat) with orthotopic tibial tumor implants into 3-week-old male and female rats to model pediatric OS. We found that rats develop reproducible primary and metastatic pulmonary tumors, and that limb amputations at 3 weeks post implantation significantly reduce the incidence of pulmonary metastasis and prevent unexpected deaths. Histologically, the primary and metastatic OSs in rats were very similar to human OS. Using immunohistochemistry methods, the study shows that rat OS are infiltrated with macrophages and T cells. A protein expression survey of OS cells reveals that these tumors express ErbB family kinases. Since these kinases are also highly expressed in most human OSs, this rat model could be used to test ErbB pathway inhibitors for therapy.

Here, a syngeneic orthotopic implantation followed by an amputation procedure of the osteosarcoma with spontaneous pulmonary metastasis that can be used for preclinical investigation of metastasis biology and development of novel therapeutics is described.

The most recent advance in the treatment of osteosarcoma (OS) occurred in the 1980s when multi-agent chemotherapy was shown to improve overall survival ...

Cancer Research

Protocol for Developing a Femur Osteotomy Model in Wistar Albino Rats

Fracture healing is a physiological process resulting in the regeneration of bone defects by the coordinated action of osteoblasts and osteoclasts. Osteoanabolic drugs have the potential to augment the repair of fractures but have constraints like high costs or undesirable side effects. The bone healing potential of a drug can initially be determined by in vitro studies, but in vivo studies are needed for the final proof of concept. Our objective was to develop a femur osteotomy rodent model that could help researchers understand the development of callus formation following fracture of the shaft of the femur and that could help establish whether a potential drug has bone healing properties. Adult male Wistar albino rats were used after Institutional Animal Ethics Committee clearance. The rodents were anesthetized, and under aseptic conditions, complete transverse fractures at the middle one-third of the shafts of the femurs were created using open osteotomy. The fractures were reduced and internally fixed using intramedullary K-wires, and secondary fracture healing was allowed to take place. After surgery, intraperitoneal analgesics and antibiotics were given for 5 days. Sequential weekly x-rays assessed callus formation. The rats were sacrificed based on radiologically pre-determined time points, and the development of the fracture callus was analyzed radiologically and using immunohistochemistry.

Here, we present a protocol to iatrogenically fracture the shaft of the femur of Wistar albino rats and follow up on the development of the callus. This femur osteotomy model can help researchers evaluate the process of fracture healing and to study how a drug could influence fracture healing.

Fracture healing is a physiological process resulting in the regeneration of bone defects by the coordinated action of osteoblasts and osteoclasts. ...

Estrogen-Like Effect of Bazi Bushen Capsule in Ovariectomized Rats

This study aims to show the estrogen-like effect of Bazi Bushen capsule (BZBS), a Chinese herbal compound, in ovariectomized mice. Female Sprague-Dawley (SD) rats were randomly divided into six groups: a sham-operated group, a model group (OVX), a progynova group, and BZBS groups (1, 2, and 4 d/kg/d). An ovariectomy was performed on all rats except those in the sham-operated group. Micro-computed tomography (micro-CT) scanning, hematoxylin and eosin (H&amp;E) staining, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) detection were performed after 4 months of BZBS treatment. As a result, compared with the OVX group, rats treated with BZBS showed an increased number and area of trabecular bone and bone marrow cells, and a decreased number of adipose cells. The bone volume, trabecular number, and trabecular thickness of the right tibia in the medication groups increased and the trabecular space decreased. The 17&#946;-estradiol and serum calcium levels in the medication groups were elevated, but the levels of serum phosphorus, sclerostin, &#946;-CTX, and TRACP-5b were decreased. In the medication groups, the RANKL and sclerostin levels were decreased, while the osteoprotegerin (OPG) level was increased. In conclusion, this protocol systematically evaluated the therapeutic effects and potential molecular mechanisms of Chinese herbal compounds in ovariectomized rats with a variety of techniques.

Presented here is a protocol to show that Bazi Bushen capsule (BZBS) can regulate the RANKL/OPG signaling pathway in the ovariectomized rodent model through its estrogen-like effect.

This study aims to show the estrogen-like effect of Bazi Bushen capsule (BZBS), a Chinese herbal compound, in ovariectomized mice. Female Sprague-Dawley ...

HE Staining and Micro-CT to Evaluate Murine Trabecular Bone Microarchitecture

Trabecular Bone Microarchitecture Evaluation in an Osteoporosis Mouse Model

Bone microstructure refers to the arrangement and quality of bone tissue at the microscopic level. Understanding the bone microstructure of the skeleton is crucial for gaining insight into the pathophysiology of osteoporosis and improving its treatment. However, handling bone samples can be complex due to their hard and dense properties. Secondly, specialized software makes image processing and analysis difficult. In this protocol, we present a cost-effective and easy-to-use solution for trabecular bone microstructure analysis. Detailed steps and precautions are provided. Micro-CT is a non-destructive three-dimensional (3D) imaging technique that provides high-resolution images of trabecular bone structure. It allows for the objective and quantitative evaluation of bone quality, which is why it is widely regarded as the gold standard method for bone quality assessment. However, histomorphometry remains indispensable as it offers crucial cellular-level parameters, bridging the gap between two-dimensional (2D) and 3D assessments of bone specimens. As for the histologic techniques, we chose to decalcify the bone tissue and then perform traditional paraffin embedding. In summary, combining these two methods can provide more comprehensive and accurate information on bone microstructure.

Author Spotlight: An Economic and Efficient Method for Quantitative Evaluation of Bone Microarchitecture in a Murine Osteoporosis Model 

This protocol presents an economical and efficient method for quantitative evaluation of bone microarchitecture in a mouse model of osteoporosis by combining Hematoxylin-Eosin (HE) staining and micro-computed tomography (Micro-CT) techniques.

Bone microstructure refers to the arrangement and quality of bone tissue at the microscopic level. Understanding the bone microstructure of the skeleton ...

Osteoporosis Management in Rats Through Lingnan Fire-Needle Therapy

Operation Procedure and Precautions of Lingnan Fire-Needle Therapy in Osteoporosis Model Rats

Compared to filiform needle therapy, fire-needle therapy has both the stimulation of needles and the warming effect of heat, making it have unexpected effects on some chronic diseases and incurable diseases. Osteoporosis (OP) has a high incidence in postmenopausal women and middle-aged and elderly men, and the treatment cycle is long. According to Traditional Chinese Medicine (TCM), Lingnan fire-needle therapy has shown potential in treating osteoporosis. However, there is still a long way to go before it can be widely used. This article focuses on the application of Lingnan fire-needle therapy in the intervention of OP in rats. It covers the selection of needle tools, acupuncture point selection, positioning of rats' bodies, and fixation methods. We also outline the steps and precautions to be taken during and after needling with fire needles. The experiment was done with three groups: a normal group, a model group, and a fire-needle group, each containing 10 rats. The rats in the fire-needle group were treated with fire-needle intervention for six sessions. After the intervention period, we collected femoral specimens and performed micro-CT scans. The results suggest that fire needling can enhance bone morphology and mineral density in OP rats. This information can serve as a methodological basis for conducting basic research on fire-needle therapy.

Author Spotlight: Exploring the Impact of Lingnan Fire-Needle Therapy in Osteoporosis Intervention

Here, we present a protocol for the application of Lingnan Fire-Needle therapy in the intervention of osteoporosis model rats.

Compared to filiform needle therapy, fire-needle therapy has both the stimulation of needles and the warming effect of heat, making it have unexpected ...

Surgical Bone Implantation Technique for Rat Tibia Models of Diabetes and Osteoporosis

The rat has long served as a valuable animal model in implant dentistry and orthopedics, particularly in studying the interactions between biomaterials and bone tissue. The rat's tibia is frequently chosen due to its easy surgical access through thin tissue layers (skin and muscle) and the flattened shape of its medial face, facilitating the surgical insertion of intraosseous devices. Additionally, this model enables the induction of specific diseases, mimicking various clinical conditions to assess biological responses to different implant conditions like geometry, surface texture, or biological cues. However, despite its robust cortical structure, certain intraosseous devices may require adaptations in design and size for successful implantation. Therefore, establishing standardized surgical methods for manipulating both soft and hard tissues in the implantation region is essential for ensuring proper implant or screw device placement, particularly in fields like implant dentistry and orthopedics. This study included eighty Sprague Dawley rats divided into two groups based on their respective diseases: Group 1 with osteoporosis and Group 2 with Type 2 Diabetes. Implantations were performed at 4 weeks and 12 weeks, with the same surgeon following a consistent surgical technique. A positive biological response was observed, indicating complete osseointegration of all implants placed. These results validate the success of the surgical protocol, which can be replicated for other studies and serve as a benchmark for the biomaterials community. Notably, osseointegration values remained stable at both 4 weeks and 12 weeks for both disease models, demonstrating a durable integration of the implant over time and emphasizing the establishment of an intimate bone connection as early as 4 weeks.

The placement of implants in a rat model is an essential experimental procedure for clinical research. This study presents a comprehensive surgical protocol for implanting titanium implants into the tibia of rat models with diabetes and osteoporosis.

The rat has long served as a valuable animal model in implant dentistry and orthopedics, particularly in studying the interactions between biomaterials ...

Elastic Tape Rat Model of Steroid-Induced Femoral Head Osteonecrosis Enhancement

Tension-Free Weight-Bearing Model of Steroid-Induced Osteonecrosis of Femoral Head in Rats

Unlike humans, rats are animals that walk on all fours, while humans are bipedal animals that stand, and the hips are subjected to tremendous pressure when walking and standing. In rat steroid-induced femoral head necrosis models, the biomechanical characteristics of the human hip under higher pressure often need to be simulated. Some scholars try to emulate the state of human hip pressure by making rats bear a certain weight, but fixing the weight-bearing object on the rat is tough. Rats can easily break free of immobilization, and sticking the weight on the rats with adhesive tape will cause the rats to suffocate or die from intestinal obstruction. Our research group used elastic therapeutic tape to perform tension-free immobilization of weight-bearing objects in rats so that the rats could breathe freely and not break away from the immobilization under weight-bearing conditions. Compared to the usual steroid-induced femoral head necrosis rat model, we found that this weight-bearing intervention can aggravate the progression of femoral head necrosis in rats.

Author Spotlight: Developing a Rat Model for Weight-Bearing Intervention to Investigate Osteonecrosis of the Femoral Head

The protocol shows building a simple and cost-effective rat weight-bearing training model for steroid-induced osteonecrosis of the femoral head using elastic therapeutic tape.

Unlike humans, rats are animals that walk on all fours, while humans are bipedal animals that stand, and the hips are subjected to tremendous pressure ...

The Creation of a Rat Model for Osteosarcopenia via Ovariectomy

Summary

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Protocol for Developing a Femur Osteotomy Model in Wistar Albino Rats

Estrogen-Like Effect of Bazi Bushen Capsule in Ovariectomized Rats

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