Name: Establishment of a Rat Model of Skeletal Muscle Injury
Uploaded: 2023-08-25T14:30:00
Description: Watch this Scientific Journal Video about Establishment of a Rat Model of Skeletal Muscle Injury at JoVE.com

establishment of a rat model of skeletal muscle injury

A Massager Based on Ding's Roll Manipulation to Treat Muscle Injury in a Rat Model

Muscle injuries are common traumatic injuries in clinical and daily life, caused by external blows (contusions) or chronic overstrain of muscle fibers (strains), etc., resulting in muscle dysfunction and pain, even seriously affecting the patient&#39;s quality of life1. Starting rehabilitation as early as possible after an acute strain injury is the key to reducing the time to return to sports2&#160;and in reducing pain3,4. In modern Western medicine, clinical first aid for muscle injuries follows the principles of rest, ice, compression, and elevation (RICE) to stop injurious bleeding into the muscle tissue5&#160;and non-steroidal anti-inflammatory drugs to relieve pain6. The discovery of novel therapies such as exosomes7&#160;and tissue engineering8&#160;became potential treatment strategies for skeletal muscle diseases, compensating for previous pharmacological treatments&#39; shortcomings. However, it can also increase the cost of treatment for patients, putting them under tremendous financial pressure9. Therefore, alternative and complementary therapies are recommended for treating musculoskeletal problems10. Tuina is widely used clinically in China as a traditional medical method and is popular among patients for its efficacy and fewer side effects. Tuina therapy for musculoskeletal disorders can alleviate pain and improve function11,12,13. Mr. Ding Jifeng, a famous Shanghai Tuina practitioner, founded Ding&#39;s roll method14. It is a unique rolling and crushing technique with a large force area, uniform and gentle force, and intense penetration.
Different animal models are based on different etiologies. They have advantages and disadvantages, and the selection of correct and appropriate animal models is of great significance to basic experiments, which helps understand the cellular and molecular signaling pathways of regeneration and repair after skeletal muscle injury to develop new therapies for treating the treatment of skeletal muscle diseases. Chemically induced models of muscle injury are widely used, with injections of skeletal muscle causing myofiber necrosis and producing regenerated areas that can effectively regenerate within 2 weeks15. Both notexin and bupivacaine can cause muscle damage. However, notexin can cause more severe myotoxic damage to skeletal muscle than bupivacaine, and natural functional recovery is relatively slower16. Drug intramuscular injection molding not only takes less time but also has controlled effects and extent of skeletal muscle damage. This quantifiable control makes successful molding less difficult15,17.
Inflammatory response is an essential biological response that has been extensively studied in the context of myopathy18,19. In the early stages of skeletal muscle injury, myofiber necrosis disrupts local muscle homeostasis, and many inflammatory cells infiltrate the injury site, secreting many pro-inflammatory cytokines19. Creatine kinase (CK) is a traditional serum biomarker for assessing skeletal muscle injury. However, it lacks tissue specificity20&#160;and sensitivity21, which limits its ability to assess the extent of drug-induced muscle damage and indirectly report the extent of muscle recovery after injury. Novel biomarkers, including fatty acid binding protein 3 (FABP3), have recently shown relatively high tissue specificity and sensitivity in rodent models of skeletal muscle injury. FABP3 is a family of binding proteins expressed primarily in cardiac and skeletal muscle cells and implicated in fatty acid metabolism, transport, and signaling22. Therefore, we chose a combination of two biomarkers, CK and FABP3, to assess the extent of notexin-induced skeletal muscle damage and recovery after treatment.
In rodents, the muscles are shallow, and the skin area is small, which also determines that the various parameters of massage in rodents will not be the same as in humans, such as in animal therapy, the massage therapist should treat them with less force using Ding&#39;s roll method, and may not be conducive to the operation of this technique due to the small size of the injured area, which can ultimately lead to a reduction in the effectiveness of the massage. Therefore, the experiment utilized the rolling massager made in-house, which conforms to the characteristics of Ding&#39;s roll method, to intervene and evaluate the therapeutic effect of the notexin-induced skeletal muscle injury model in rats, which helps to standardize the parameters of Tuina in experimental animal studies in order to profoundly investigate the molecular mechanism of action of Tuina, a traditional Chinese medicine treatment method, on musculoskeletal diseases.

Author Spotlight: Performing Tuina Massage in Rats Using a Self-Made Massager 

Mimicking Ding's Roll Method on Notexin-Induced Muscle Injury in Rats

The scope of our research is the biological mechanism of tuina in the treatment of musculoskeletal diseases. Here we are trying to make the self-made tuina device to standardize and effectively perform tuina treatments on laboratory animals. We are addressing the inability to perform this rolling manipulation with pairs by creating a massager that can simulate this rolling manipulation on rats, and verifying the effectiveness of the massager on rats with muscle injuries.We will focus on the questions of how efficacious the rolling massager is on the skeletal muscle injury in rats under different parameters in future standardized research.

Watch this Scientific Journal Video about Establishment of a Rat Model of Skeletal Muscle Injury at JoVE.com

Establishment of a Rat Model of Skeletal Muscle Injury  

Begin by randomly dividing the rats into three groups of eight rats each, including control, notexin, and notexin with tuina groups. Remove the hair from the right lower limb with hair removal cream after anesthetizing the rat. Then disinfect the skin with three alternating rounds of iota four disinfecting solution and 75%alcohol in a circular outward motion.To establish the skeletal muscle injury model, use a one milliliter syringe with a 30 gauge needle to inject the notexin solution intramuscularly into the gastrocnemius muscle in only one leg. Wait for three seconds before pulling out the needle. Inject the rats in the control group with 200 microliters of saline solution.Move anesthetized rats to empty cages with clean bedding. Visually observe the tissue color and respiratory rate until the rats regain sufficient consciousness. Return the rats to the home cage and typically rear them for 24 hours.The morphological properties of rat skeletal muscle after injury were observed by hematoxylin and eosin staining. The gastrocnemius muscle injured by notexin injection showed the rupture of many muscle cells compared to controls. The cells were atrophic, necrotic, and irregularly arranged, with a high infiltration of neutrophils and lymphocytes around the affected area.