BACKGROUND: The effect of air pollution on annual change rates in grip strength and body composition in the elderly is unknown. OBJECTIVES: This study evaluated the effects of long-term exposure to ambient air pollution on change rates of grip strength and body composition in the elderly. METHODS: In the period 2016-2020, grip strength and body composition were assessed and measured 1-2 times per year in 395 elderly participants living in the Taipei basin. Exposure to ambient fine particulate matters (PM_2.5), nitric dioxide (NO₂), and ozone (O₃) from 2015 to 2019 was estimated using a hybrid Kriging/Land-use regression model. In addition, long-term exposure to carbon monoxide (CO) was estimated using an ordinary Kriging approach. Associations between air pollution exposures and annual changes in health outcomes were analyzed using linear mixed-effects models. RESULTS: An inter-quartile range (4.1 µg/m³) increase in long-term exposure to PM_2.5 was associated with a faster decline rate in grip strength (-0.16 kg per year) and skeletal muscle mass (-0.14 kg per year), but an increase in body fat mass (0.21 kg per year). The effect of PM_2.5 remained robust after adjustment for NO₂, O₃ and CO exposure. In subgroup analysis, the PM_2.5-related decline rate in grip strength was greater in participants with older age (>70 years) or higher protein intake, whereas in skeletal muscle mass, the decline rate was more pronounced in participants having a lower frequency of moderate or strenuous exercise. The PM_2.5-related increase rate in body fat mass was higher in participants having a lower frequency of strenuous exercise or soybean intake. CONCLUSIONS Among the elderly, long-term exposure to ambient PM_2.5 is associated with a faster decline in grip strength and skeletal muscle mass, and an increase in body fat mass. Susceptibility to PM_2.5 may be influenced by age, physical activity, and dietary protein intake; however, these modifying effects vary across different health outcomes, and further research is needed to clarify their mechanisms and consistency.
Humans ; Hand Strength ; Aged ; Male ; Female ; Environmental Exposure/adverse effects* ; Follow-Up Studies ; Taiwan ; Air Pollution/adverse effects* ; Particulate Matter/adverse effects* ; Muscle, Skeletal/drug effects* ; Air Pollutants/adverse effects* ; Ozone/adverse effects* ; Aged, 80 and over ; Adipose Tissue/drug effects* ; Body Composition/drug effects* ; Nitrogen Dioxide/adverse effects*

BACKGROUND: High visceral fat mass (FM) is associated with a high risk of cardiometabolic morbidity. Meanwhile, loss of skeletal muscle (lean mass, LM) has been suggested to contribute to metabolic diseases. METHODS: We investigated associations between cardiometabolic diseases and dual energy X-ray absorptiometry (DXA)-measured body composition indices, including the FM index (FM/height²), percent body fat, trunk-to-appendicular fat ratio (TAR), trunk-to-leg fat ratio (TLR), LM index (LM/height²) and FM-to-LM ratio in 595 community-dwelling elderly Japanese men (mean age, 74 years; standard deviation, 6; range, 65 to 94). Hypertension was identified as high blood pressure and/or the use of antihypertensive drugs. Diabetes was identified as high hemoglobin A1c and/or the use of antidiabetic drugs. The ability of DXA-based indices to discriminate between the presence and absence of cardiometabolic diseases was evaluated using area under the curve (AUC) calculated by receiver operating characteristic curve analysis. RESULTS: Body mass index, FM index, percent body fat, TAR, TLR and FM-to-LM ratio were significantly associated with hypertension (P < 0.05). TAR and TLR, but not body mass index, FM index, percent body fat, LM index and FM-to-LM ratio, showed significant positive associations with diabetes. The AUC for the LM index was significantly lower than those for the FM index, percent body fat and FM-to-LM ratio. No associations were observed between the LM index and hypertension, dyslipidemia and diabetes. CONCLUSION The association between cardiometabolic function and LM, which includes skeletal muscle, may not be as pronounced or stronger than associations between cardiometabolic function and FM. Further detailed studies are needed to clarify how skeletal muscle contributes to cardiometabolic disease.
Humans ; Male ; Absorptiometry, Photon ; Aged ; Japan/epidemiology* ; Body Composition ; Aged, 80 and over ; Hypertension/epidemiology* ; Cardiovascular Diseases/epidemiology* ; Body Mass Index ; Muscle, Skeletal ; Osteoporosis/epidemiology* ; Diabetes Mellitus/epidemiology* ; Risk Factors ; East Asian People

Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson tumor, is a rare vascular benign tumor of blood vessels. It may occur in any part of the body, especially the deep dermis and subcutaneous tissue of the head, neck, fingers and trunk. The imaging and histopathology of IPEH are similar to hemangiosarcoma, especially in the case of active vascular endothelial hyperplasia. IPEH is a reactive proliferative lesion of vascular intima. The etiology is still unclear. After some studies showed that IPEH was a benign lesion, few reports on the etiology of it were reported. IPEH is usually limited to the thrombotic vessels or lumens of vascular malformations, usually accompanied by a clear history of trauma. IPEH usually does not cause any symptoms. It looks like a slow-growing lump. Some cases have been reported with pain and swelling. Although IPEH is relatively rare, its accurate diagnosis is crucial because it may be similar to malignant angiogenic lesions in clinical practice. There were few reports of cases related to intravascular papillary endothelial hyperplasia located in the sternocleidomastoid muscle after reviewing the domestic and foreign literature in recent 10 years. This case reports that a young male, who was admitted to the hospital one month after finding a subcutaneous tumor in the left neck. After admittance, relevant preoperative examinations were completed. After multi-disciplinary discussion and elimination of surgical contraindications, a specific surgical plan was formulated. The tumor was removed under local anesthesia on the second day after admission. During the operation, it was found that the tumor was located between the sternocleidomastoid muscle bundles, and it was sent for pathologic examination. Paraffin section pathology was reported after operation. Histological examination showed that the morphology was consistent with vascular endothelial papillary hyperplasia. There were no related surgical complications and recurrence in the 3-month follow-up. The purpose of this paper is to provide clinicians with a certain understanding of this rare disease through the report of this case of IPEH, and to identify it in later clinical work, and at the same time, to avoid confusion with malignant diseases, such as hemangiosarcoma, leading to unnecessary treatment and increase the cost of treatment.
Humans ; Male ; Endothelium, Vascular/pathology* ; Hemangioendothelioma/surgery* ; Hyperplasia/pathology* ; Neck Muscles/surgery* ; Vascular Neoplasms/pathology*

This study aims to evaluate the application of flower petal-structured electrodes in pulsed field ablation (PFA) technology, with a particular focus on their performance in myocardial tissue ablation. Through a combination of simulation techniques and in vitro experiments, the study investigates the effects of different voltage levels, electrode-to-tissue contact distances, and their impact on ablation depth, continuity, and transmurality. The research methods include the construction of a myocardial tissue simulation model, electric field distribution simulation using COMSOL Multiphysics, and in vitro ablation experiments on potato tissue. The results indicate that as voltage increases, the ablation depth significantly increases. At a voltage of 2500 V, a transmural ablation depth of 4 mm can be achieved, and the ablation area remains relatively continuous. The in vitro experiments confirm the consistency of the simulation results, and pulsed field ablation does not induce significant temperature rise, confirming its non-thermal characteristic. The conclusion suggests that PFA technology requires less electrode contact and offers higher ablation efficiency, providing a new technological pathway for the clinical treatment of atrial fibrillation and effectively reducing the risk of complications associated with traditional ablation techniques.
Electrodes ; Catheter Ablation/instrumentation* ; Computer Simulation ; Flowers ; Atrial Fibrillation/surgery* ; Myocardium

INTRODUCTION: Diaphragm rupture (DR) is a rare pathological event usually caused by trauma. We aimed to analyse the characteristics of acute diaphragmatic injuries due to trauma and the treatment of such injuries. METHODS: This study included the data of 15 patients who sustained diaphragmatic injuries due to trauma and underwent surgery at the Diyarbakır Gazi Yaşargil Training and Research Hospital General Surgery Service between January 2016 and December 2019. RESULTS: There were 240 patients who presented with abdominal trauma during the study period, and DR was detected in 15 (6.25%) of these patients. The male to female ratio was 14 to 1, and the average age of the patients was 29.66 ± 10.56 (15-46) years. The most common cause of diaphragmatic injury was penetrating abdominal injuries (86.7%). Blunt abdominal trauma accounted for 13.3% of the DR cases. Preoperative shock was present in four (26.7%) patients. Preoperative diagnosis was made in only one (6.7%) of 15 patients with DR. Other patients were diagnosed during operation. Thirteen (86.7%) patients had additional organ injuries, and two patients had isolated diaphragmatic injuries. The most frequently injured organ was the lung ( n = 7, 46.6%). Complications developed in six patients (morbidity rate 40%), and pulmonary complications were most frequently encountered ( n = 5, 33.3%). The mortality rate was 6.7%. CONCLUSION As traumatic DRs are uncommon and often associated with additional organ injuries, a careful general assessment of the patient should be made.
Humans ; Male ; Female ; Adult ; Diaphragm/surgery* ; Middle Aged ; Adolescent ; Young Adult ; Abdominal Injuries/complications* ; Rupture/surgery* ; Wounds, Penetrating/surgery* ; Wounds, Nonpenetrating/complications* ; Retrospective Studies ; Turkey/epidemiology*

OBJECTIVE: To assess the impacts of electroacupuncture (EA) on the gait, oxidative stress, inflammatory reaction, and protein degradation in the rats of denervated skeletal muscle atrophy, and explore the potential mechanism of EA for alleviating denervated skeletal muscle atrophy. METHODS: Forty male SD rats, 8 weeks old, were randomly assigned to a sham-surgery group, a model group, an EA group, and a p38 MAPK inhibitor group, with 10 rats in each group. The right sciatic nerve was transected to establish a rat model of denervated skeletal muscle atrophy in the model group, the EA group and the p38 MAPK inhibitor group. In the sham-surgery group, the nerve was exposed without transection. One day after successful modeling, the rats in the EA group received EA at "Huantiao" (GB30) and "Zusanli" (ST36) on the right side, using a continuous wave with a frequency of 2 Hz and current intensity of 1 mA, for 15 min in each session, EA was delivered once a day, 6 times a week. In the p38 MAPK inhibitor group, the rats received the intraperitoneal injection with SB203580 (5 mg/kg), once a day, 6 times a week. The intervention was composed of 3 weeks in each group. After the intervention completion, the CatWalk XT 10.6 animal gait analysis system was used to record the gait parameters of rats. The wet weight ratio of the gastrocnemius muscle was calculated after the sample collected. Using HE staining, the fiber morphology and cross-sectional area of the gastrocnemius muscle were observed; ELISA was employed to measure the content of interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α in the gastrocnemius muscle; the biochemical hydroxyamine method was adopted to detect the content of superoxide dismutase (SOD) and malondialdehyde (MDA) in the gastrocnemius muscle; with immunohistochemistry and Western blot used, the expression of p38 mitogen-activated protein kinase (p38 MAPK), phosphorylated (p)-p38 MAPK, muscle atrophy F-box gene (Atrogin-1), muscle RING finger 1 (Murf-1), nuclear factor E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) was detected in the gastrocnemius muscle. RESULTS: Compared to the sham-surgery group, in the model group, the standing duration, the swing time and the step cycle were increased (P<0.001), the footprint area of the maximum contact time, the print area, the average intensity of the maximum contact time, the average intensity, the swing speed, and the step length were decreased (P<0.001); the wet weight ratio of gastrocnemius muscle and fiber cross-sectional area were reduced (P<0.001); the content of IL-6, IL-1β, TNF-α and MDA in gastrocnemius muscle elevated (P<0.001), and that of SOD reduced (P<0.001); the positive and protein expression of p-p38 MAPK, Atrogin-1 and Murf-1 elevated (P<0.001) and that of Nrf2 and HO-1 dropped (P<0.001). When compared with the model group, in the EA group and the p38 MAPK inhibitor group, the standing duration, the swing time and the step cycle decreased (P<0.01), the footprint area of the maximum contact time, the print area, the average intensity of the maximum contact time, the average intensity, the swing speed, and the step length increased (P<0.01); the wet weight ratio of gastrocnemius muscle and fiber cross-sectional area were improved (P<0.01, P<0.05); the content of IL-6, IL-1β, TNF-α and MDA in gastrocnemius muscle dropped (P<0.05, P<0.01), and that of SOD elevated (P<0.01, P<0.05); the positive and protein expression of p-p38 MAPK, Atrogin-1 and Murf-1 dropped (P<0.01, P<0.05) and that of Nrf2 and HO-1 increased (P<0.01, P<0.05). CONCLUSION Electroacupuncture may alleviate skeletal muscle atrophy in denervated skeletal muscle atrophy rats by mediating the p38 MAPK activity, thereby suppressing oxidative stress, inflammatory reaction, and protein degradation.
Animals ; Electroacupuncture ; Male ; Rats ; p38 Mitogen-Activated Protein Kinases/genetics* ; Rats, Sprague-Dawley ; Muscular Atrophy/metabolism* ; Muscle, Skeletal/metabolism* ; Humans ; Signal Transduction ; Superoxide Dismutase/genetics* ; Tumor Necrosis Factor-alpha/genetics* ; Oxidative Stress ; MAP Kinase Signaling System ; Acupuncture Points

OBJECTIVE: To observe the effects of antagonistic needling therapy on lower limb spasticity and the muscle morphology of the tibialis anterior and gastrocnemius in patients with stroke. METHODS: A total of 100 patients with post-stroke lower limb spasticity were randomly divided into an antagonistic needling group (50 cases, 1 case dropped out) and a routine acupuncture group (50 cases, 1 case dropped out). Both groups received basic treatment and rehabilitation training. The routine acupuncture group was treated with scalp acupuncture at anterior oblique line of vertex-temporal and vertex lateral line 1, combined with body acupuncture at Jianyu (LI15), Hegu (LI4), Zusanli (ST36), Taichong (LR3), etc. on the affected side, with Quchi (LI11) and Hegu (LI4), Zusanli (ST36) and Fenglong (ST40), Yanglingquan (GB34) and Taichong (LR3) connected to an electroacupuncture device, using disperse wave at 2 Hz of frequency. The antagonistic needling group used the same scalp and upper limb acupoints as the routine acupuncture group, with additional antagonistic needling on the lower limb at Yanglingquan (GB34), Qiuxu (GB40), Jiexi (ST41), and Xuanzhong (GB39) on the affected side, with Quchi (LI11) and Hegu (LI4), Yanglingquan (GB34) and Qiuxu (GB40), Jiexi (ST41), and Xuanzhong (GB39) connected to an electroacupuncture device, using disperse wave at 2 Hz of frequency. Both groups received treatment once daily for 6 consecutive days per course, with a total of 4 courses. The modified Ashworth scale (MAS), Holden functional ambulation classification (FAC), lower limb Fugl-Meyer assessment (FMA), composite spasticity scale (CSS), and musculoskeletal ultrasound parameters (thickness and fiber length of the tibialis anterior and gastrocnemius, and pennation angle of the gastrocnemius on both sides) were evaluated before and after treatment. Clinical efficacy was compared between the two groups. RESULTS: Compared before treatment, the MAS grades and CSS scores were decreased in both groups after treatment (P<0.01), with greater reductions in the antagonistic needling group (P<0.05, P<0.01). FAC grades and FMA scores were increased in both groups after treatment (P<0.01, P<0.05), with greater improvements in the antagonistic needling group (P<0.05). The muscle thickness, fiber length of the tibialis anterior, the muscle thickness, fiber length and pennation angle of the gastrocnemius on the affected side were improved in both groups after treatment (P<0.01), with greater improvements in the antagonistic needling group (P<0.01, P<0.05). On the unaffected side, these parameters were also increased after treatment in both groups (P<0.01, P<0.05), but the antagonistic needling group showed smaller increases than the routine acupuncture group (P<0.01, P<0.05). The total effective rate in the antagonistic needling group was 91.8% (45/49), higher than 81.6% (40/49) in the routine acupuncture group (P<0.05). CONCLUSION Antagonistic needling could effectively reduce spasticity, improve motor function, and enhance muscle structure in patients with post-stroke lower limb spasticity.
Humans ; Male ; Female ; Acupuncture Therapy ; Middle Aged ; Muscle Spasticity/pathology* ; Aged ; Stroke/physiopathology* ; Lower Extremity/physiopathology* ; Acupuncture Points ; Adult ; Muscle, Skeletal/pathology* ; Treatment Outcome

OBJECTIVE: To observe the effect of electroacupuncture (EA) pretreatment of "biaoben acupoint combination" on cardiomyocyte mitochondrial fission in the rats with myocardial ischemia-reperfusion injury (MIRI) and explore its mechanism. METHODS: Fifty male SD rats were randomly divided into a sham-operation group, a model group, an EA pretreatment group, an EA pretreatment + Compound C group and an EA pretreatment+ML385 group, 10 rats in each group. In the EA pretreatment, the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, EA was delivered at bilateral "Neiguan" (PC6), "Zusanli" (ST36) and "Guanyuan" (CV4) for 20 min, with continuous wave and 2 Hz of frequency, 1 mA of current, once daily for consecutive 7 days. On day 8, in the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, 30 min before model preparation, the intraperitoneal injection with Compound C (0.3 mg/kg) and ML385 (30 mg/kg) was administered respectively. Except in the sham-operation group, the ligation of the left anterior descending coronary artery was performed to prepare MIRI rat model in the rest groups. In the sham-operation group, the thread was not ligated. After modeling, the content of reactive oxygen species (ROS) in the ischemic area was measured by flow cytometry, superoxide dismutase (SOD) was detected using xanthine oxidase method, and malondialdelyde (MDA) was detected using thiobarbituric acid (TBA) chromatometry. The morphology of myocardial tissue in the ischemic area was observed with HE staining, and the mitochondria ultrastructure of cardiomyocytes observed under transmission electron microscopy. Using immunofluorescence analysis, the positive expression of mitochondrial fission factor (MFF), mitochondrial fission 1 protein antibody (Fis1) and dynamin-related protein 1 (Drp1) was detected; and with immunohistochemical method used, the protein expression of adenosine monophosphate-activated protein kinase (AMPK), nuclear factor E2-associated factor2 (Nrf2) and Drp1 in the ischemic area was detected. RESULTS: Compared with the sham-operation group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 increased in the model group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 decreased (P<0.01), and the protein expression of Drp1 elevated (P<0.01). Compared with the model group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 were dropped in the EA pretreatment group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 rose (P<0.01), and the protein expression of Drp1 declined (P<0.01); and in the EA pretreatment+Compound C group and the EA pretreatment+ML385 group, the positive expression of MFF, Fis1 and Drp1, and the protein expression of Drp1 were all reduced (P<0.01). When compared with the EA pretreatment + Compound C group and the EA pretreatment+ML385 group, the content of ROS and MDA in the myocardial tissue of the ischemic area, and the positive expression of MFF, Fis1 and Drp1 were dropped in the EA pretreatment group (P<0.01); the content of SOD and the protein expression of AMRK and Nrf2 rose (P<0.01, P<0.05), and the protein expression of Drp1 decreased (P<0.05). In comparison with the model group, the EA pretreatment+Compound C group and the EA pretreatment+ML385 group, the cardiac muscle fiber rupture, cell swelling and mitochondrial disorders were obviously alleviated in the EA pretreatment group. The morphological changes were similar among the model group, the EA pretreatment+Compound C group and the EA pretreatment+ML385 group. CONCLUSION Electroacupuncture pretreatment of "biaoben acupoint combination" attenuates myocardial injury in MIRI rats, probably through promoting the phosphorylation of AMPK and Nrf2, inhibiting the excessive mitochondrial fission induced by Drp1, and reducing mitochondrial dysfunction caused by mitochondrial fragmentation and vacuolation.
Animals ; Electroacupuncture ; Male ; Rats, Sprague-Dawley ; Myocardial Reperfusion Injury/physiopathology* ; Myocytes, Cardiac/cytology* ; Rats ; Acupuncture Points ; Mitochondrial Dynamics ; Humans ; Reactive Oxygen Species/metabolism* ; NF-E2-Related Factor 2/genetics* ; Superoxide Dismutase/metabolism*

OBJECTIVE: To observe the effects of moxibustion at "Xinshu" (BL15) and "Feishu" (BL13) on myocardial transferrin receptor 1 (TfR1), ferroptosis suppressor protein 1 (FSP1), atrial natriuretic peptide (ANP), and typeⅠcollagen myocardial collagen fibers (CollagenⅠ) in rats with chronic heart failure (CHF), and to explore the mechanism of moxibustion for ameliorating myocardial fibrosis and improving cardiac function in CHF. METHODS: Fifty SD rats were randomly divided into a normal group (n=10) and a modeling group (n=40). The CHF model was established in the modeling group by ligating the left anterior descending coronary artery. After successful modeling, the rats were randomly divided into a model group (n=9), a moxibustion group (n=8), a rapamycin (RAPA) group (n=9), and a moxibustion+RAPA group (n=9). In the moxibustion group, moxibustion was delivered at bilateral "Feishu"(BL13) and "Xinshu" (BL15), 15 min at each point in each intervention, once daily, for 4 consecutive weeks. In the RAPA group, RAPA solution was administered intraperitoneally at a dose of 1 mg/kg, once daily for 4 consecutive weeks. In the moxibustion+RAPA group, RAPA solution was administered intraperitoneally after moxibustion. Ejection fraction (EF) and left ventricular fractional shortening (FS) were measured after modeling and intervention. After intervention, morphology of cardiac muscle was observed using HE staining and Masson's trichrome staining. Total iron content in myocardial tissue was detected using a colorimetric method. Western blot and qPCR were adopted to detect the protein and mRNA expression of TfR1, FSP1, ANP, and CollagenⅠ in myocardial tissue. RESULTS: Compared with the normal group, the EF and FS values decreased (P<0.01); necrosis, edema, degeneration, and arrangement disorder were presented in cardiomyocytes; inflammatory cells were obviously infiltrated, the structure of myocardial fibers was disarranged, the collagen fibers were obviously deposited and fibrosis increased (P<0.01); the total iron content and the protein and mRNA expression of TfR1, ANP, and CollagenⅠ in myocardial tissue were elevated (P<0.01), while the protein and mRNA expression of FSP1 were reduced (P<0.01) in the model group. Compared with the model group, the moxibustion group showed that EF and FS increased (P<0.01); myocardial cell morphology was improved, and myocardial fibrosis was alleviated (P<0.01); the total iron content and the protein and mRNA expression of TfR1, ANP, and CollagenⅠ in myocardial tissue decreased (P<0.01), while the protein and mRNA expression of FSP1 increased (P<0.01, P<0.05). Compared with the model group, the myocardial fibrosis was increased (P<0.05); the total iron content and the protein and mRNA expression of TfR1, ANP, CollagenⅠ in myocardial tissue were increased (P<0.01), while protein and mRNA expression of FSP1 decreased (P<0.01) in the RAPA group. When compared with the RAPA group and the moxibustion + RAPA group, EF and FS were elevated (P<0.01, P<0.05); myocardial cells were improved in morphology, the total iron content and the protein and mRNA expression of TfR1, ANP, and CollagenⅠ in myocardial tissue decreased (P<0.01), while protein and mRNA expression of FSP1 increased (P<0.01) in the moxibustion group. In comparison with the moxibustion + RAPA group, the RAPA group showed the decrease in EF and FS (P<0.01), the worsened myocardial fibrosis (P<0.01), the increase in the total iron content and the protein and mRNA expression of TfR1, ANP, and CollagenⅠ in myocardial tissue (P<0.01), and the decrease in the protein and mRNA expression of FSP1 (P<0.01). CONCLUSION Moxibustion at "Feishu" (BL13) and "Xinshu" (BL15) can slow down the process of myocardial fibrosis and improve cardiac function in CHF rats. The mechanism of moxibustion may be related to inhibiting ferroptosis through regulating autophagy.
Animals ; Rats ; Heart Failure/physiopathology* ; Moxibustion ; Rats, Sprague-Dawley ; Male ; Receptors, Transferrin/genetics* ; Myocardium/metabolism* ; Acupuncture Points ; Humans ; Chronic Disease/therapy* ; Antigens, CD/metabolism*

OBJECTIVE: To investigate the potential mechanism by which electroacupuncture (EA) induces macrophage polarization to promote muscle satellite cell proliferation and differentiation, accelerating the repair of acute skeletal muscle injury. METHODS: Forty-two SPF-grade SD rats were randomly divided into three groups: a blank group (n=6), a model group (n=18), and an EA group (n=18). The model and EA groups established acute blunt contusion model of the right gastrocnemius muscle using a self-made striking device. From day 1 after modeling, rats in the EA group received EA at "Chengshan" (BL57) and "Yanglingquan" (GB34) on the right side, using disperse-dense wave with a frequency of 2 Hz/100 Hz and a current of approximately 2 mA. The EA treatment was administered once daily for 30 minutes for 3, 7, or 14 days based on the designated sampling time points. Gait analysis was performed using the Cat Walk XT^TM system. Hematoxylin-eosin (HE) staining was used to observe the morphological changes in the gastrocnemius muscle. Masson staining was applied to evaluate collagen fiber content. Immunofluorescence was used to detect the expression of proliferating cell nuclear antigen (PCNA) in muscle satellite cells. Immunohistochemistry was used to assess the expression levels of CD68 and CD206, markers of macrophages. Serum levels of pro-inflammatory cytokines (TNF-α, IL-1β) and anti-inflammatory cytokines (IL-10, IL-13) were detected using ELISA. RESULTS: Compared with the blank group, the model group showed a significant reduction in average movement speed on days 3 and 7 after modeling (P<0.05), and a decrease in the right hind limb stride length on day 3 (P<0.05). Compared with the model group, the EA group showed increased average movement speed and right hind limb stride length on day 7 (P<0.05). In the blank group, the gastrocnemius muscle on the right side showed uniform and consistent inter-fiber spacing, with neatly and regularly arranged muscle cells. In contrast, the model group exhibited enlarged inter-fiber spacing, edema, and significant infiltration of red blood cells and inflammatory cells, with progressively increasing fibrosis over time. By day 14 after modeling, the EA group showed a return to baseline levels of inflammatory cell infiltration, and the degree of fibrosis was significantly lower than that observed in the model group. Compared with the blank group, the ratio of collagen fibers in the gastrocnemius muscle of the model group increased significantly on days 3, 7, and 14 after modeling (P<0.05). Compared with the model group, the EA group exhibited a lower collagen fiber ratio on days 3, 7, and 14 (P<0.05). Compared with the blank group, PCNA positive expression in the gastrocnemius muscle of the model group was significantly increased on days 3, 7, and 14 after modeling (P<0.05). Compared with the model group, the EA group exhibited significantly higher PCNA positive expression on days 3 and 7 (P<0.05). Compared with the blank group, the model group showed a significant increase in CD68-positive macrophage expression in the gastrocnemius muscle on day 3 after modeling (P<0.05), while CD206-positive macrophage expression increased on days 3, 7, and 14 (P<0.05). Compared with the model group, CD68 expression was significantly lower in the EA group on day 3 (P<0.05), whereas CD206 expression was significantly higher on days 3 and 7 (P<0.05), peaking on day 7 with CD206 expression. Compared with the blank group, serum TNF-α levels were significantly elevated in the model group on days 3 and 7 after modeling (P<0.05), while serum IL-1β levels were increased on days 3, 7, and 14 (P<0.05). Serum IL-10 and IL-13 levels were significantly higher on day 7 after modeling (P<0.05). Compared with the model group, the EA group exhibited lower serum TNF-α level on day 3 (P<0.05) and reduced serum IL-1β levels on days 3 and 7 (P<0.05), while serum IL-10 and IL-13 levels were significantly increased on day 7 (P<0.05). CONCLUSION EA could promote the repair of acute blunt contusion-induced gastrocnemius muscle injury by regulating the proliferation and differentiation of muscle satellite cells. This process is closely related to macrophage polarization.
Animals ; Electroacupuncture ; Rats, Sprague-Dawley ; Rats ; Macrophages/immunology* ; Muscle, Skeletal/immunology* ; Male ; Humans ; Female ; Tumor Necrosis Factor-alpha/immunology* ; Cell Proliferation