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Evaluation of Muscle Performance in Mice by Treadmill Exhaustion Test and Whole-limb Grip Strength Assay
通过跑步机疲劳测试和全肢握力测定评估小鼠肌肉性能   

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Abstract

In vivo muscle function testing has become of great interest as primary phenotypic analysis of muscle performance. This protocol provides detailed procedures to perform the treadmill exhaustion test and the whole-limb grip strength assay, two methods commonly used in the neuromuscular research field.

Keywords: Exhaustion test(疲劳测试), Grip strength(握力), Mice(小鼠), Muscle(肌肉), Treadmill(跑步机)

Background

Muscle diseases usually lead to alterations in skeletal muscle function. Non-invasive in vivo tests that can evaluate muscle performance are therefore of considerable value as primary phenotypic screening. Here, we describe how to perform the treadmill exhaustion test, which evaluates exercise capacity and endurance, and the limb grip strength assay, which measures muscular strength. In the treadmill exhaustion test, the mice are forced to run to exhaustion over a conveyor belt with gradually increasing speed. The limb grip strength assay uses a horizontal grip–that is grasped by the mouse–to measure the maximum force that is required to make the mouse release it. These tests can be easily customized to evaluate muscle performance under different situations, such as after therapeutic interventions or regeneration (Benchaouir et al., 2007; Puzzo et al., 2016), or to study the potential roles of specific genes on muscle physiopathology (Waning et al., 2015; Bi et al., 2016; Yue et al., 2016).

Materials and Reagents

  1. Record sheet
  2. Appropriate mouse strain and housing facility
  3. Ethanol (70%), or disinfectant wipes, mild solution of detergent and water

Equipment

  1. Treadmill exhaustion test
    1. Timer
    2. Plastic tray
    3. Treadmill system: Exer 3/6 treadmill and treadmill controller (Columbus Instruments, model: Exer 3/6 ) (Figure 1)
    4. Computer and software provided by the manufacturer


      Figure 1. Treadmill system and components

  2. Whole-limb grip strength assay
    1. Grip strength meter (Columbus Instruments, model: 1027SM Grip Strength Meter with Single Sensor ). The apparatus includes a grid that is connected to a force transducer, a digital display (AMETEK, Chatillon, model: DFE2-002 ), and a base that elevates it (Figure 2)
    2. Scale


      Figure 2. Grip strength meter

Software

  1. Treadmill software (Columbus Instruments, OH, USA)

Procedure

  1. Treadmill exhaustion test
    1. Training
      1. Set the treadmill to desired angle of inclination or declination. In this instrument the angle of inclination is set by the location of the spring pin in holes of the inclination rod. Uphill inclinations (slopes of 10%) are commonly used for this test (Bi et al., 2016; Nie et al., 2016; Yue et al., 2016). Uphill running involves concentric muscle contraction and increases the muscle work for the animals as compared with running on a flat surface, leading to faster exhaustion. Downhill running may also be used to examine eccentric muscle contraction.
      2. Place a plastic tray underneath the instrument to collect feces and urine that could be produced during the test.
      3. Insert the lane dividers into the slots of the treadmill.
      4. Switch on the treadmill controller.
      5. Adjust the electric shock frequency and intensity (Figure 3A). In this apparatus, the electric stimuli are pulses (200 msec/pulse) of electric current with adjustable pulse repetition rate (1, 2 or 3 times per second, Hz) and intensity (suggested: 3 Hz, 1.22 mA; respectively).
      6. Place the mice on the treadmill belt and cover with the lid.
      7. Turn the shock grids on for each line by setting each toggle switch toward the grids (the stimulus indicator will begin to flash).
      8. Adjust the belt speed to 10 m/min using the ‘speed’ knob located in the treadmill controller. Set the ‘treadmill belt’ toggle switch to ‘run’ (Figure 3B).


        Figure 3. Electric shock stimulus (A) and speed (B) adjustment using the treadmill controller

      9. Start a timer. Allow mice to run for 5 min.
      10. After this time, set the ‘treadmill belt’ toggle back to ‘stop’.
      11. Disable the shock stimulus for all lanes.
      12. Remove animals and return each mouse to its cage.
      13. Clean the treadmill belt and grid with 70% ethanol and repeat steps A1f to A1l if additional mice have to be trained.
      14. Turn off the machine.
      15. Wash the feces collecting tray and the lane dividers.
      16. Repeat the training session during 3 consecutive days prior to the test.
    2. Test
      1. Perform the steps A1a through A1e of the previous section.
      2. Turn on the computer and start the treadmill software. Setup a new experiment as follows:
        1. Select ‘Experiment >> Run’ from the main menu.
        2. Click the ‘Profile Mode’ tab at the top of the window.
        3. Use the computer mouse to select the text boxes and enter the corresponding parameters (see Table 1, Figure 4A). In this test, the speed is initially set at 10 m/min for 5 min, and it is increased 2 m/min every 2 min up to a maximum speed of 46 m/min is reached (Bi et al., 2016).


          Figure 4. Treadmill Software. A. Creating a profile. A Treadmill exercise profile is created by selecting the text (white) boxes with the computer mouse and manually entering the corresponding parameters; more steps are added by clicking ‘add period’. This profile can be saved and used later to test other mice. To do this, click ‘Load’ in the profile mode screen and select the saved file. B. Running the experiment. A graphical representation is automatically generated to show the relative speed and time of the entire profile. The vertical red bar in the graph points out the current position, while an arrow within the step column of the profile table marks the step currently in use. Step time: informs about the time remaining within the current step; Spd (m/m): reports the current speed of the treadmill belt; Dist Tr (m): reports the total distance the treadmill belt has moved.

          Table 1. Treadmill exhaustion test steps


      3. Set the ‘Treadmill belt’ toggle switch to ‘Run’ and enable the electric shock.
      4. Click the ‘Start’ button. A ‘Save Experiment Data File’ window will open (save as a .csv file).
      5. Load the mice into separate lanes on the treadmill belt and then click ‘OK’.
      6. Run the experiment until the mice are exhausted or the maximal speed is achieved.  
        1. When a mouse becomes exhausted, write down the time, speed, and distance that are displayed at that moment on the screen (see Figure 4B) and turn off the shock grid for its lane. Remove the mouse from the treadmill.
          There are different ways to define exhaustion and the same criteria must be used throughout the experiment. For example, the exhaustion may be defined as the inability of the animal to run on the treadmill for 10 sec despite mechanical prodding (Bi et al., 2016; Yue et al., 2016).
        2. When no mice remain on the treadmill or the maximal speed is reached, stop the experiment and turn off the shock grids.
      7. To test additional mice clean the treadmill and grid with 70% alcohol and repeat the described procedure. (Click ‘Load’ in the profile mode screen and select the saved file generated previously in order not to have to enter again all the data manually, then click ‘Start’). Each mouse is tested one time the day after the last training session. We recommend to use at least five animals to ensure high statistical power. Due to potential variances in the sex, age, and genetic background of mice, calculation of the number of animals required for this test should be performed by a power analysis.

  2. Whole-limb grip strength assay
    1. Place the mice in the testing room for 10 min to acclimate (leave the room during this time).
    2. Put the force meter on a firm, flat surface.
    3. Connect the grid to the digital force gauge and clean it with 70% ethanol or disinfectant wipe.
    4. Set up the grip strength meter (GSM):
      1. Turn on the GSM.
      2. Push the bottom under the ‘Mode’ option to select the Peak Tension (T-PK) mode (this displays the peak force applied to the GSM as a result of pulling away from the GSM). Press ‘Home’ to return to the main screen.
      3. Press the ‘Units’ bottom to select the units of force (e.g., Newton, N)
      4. Press ‘Zero’ to tare the GSM.
    5. Testing animals (Figure 5):
      1. Remove the mouse to be tested from the cage and place it over the top of the grid. Allow the mouse to grasp the grid with all four paws.
        The mouse can be held by the base of the tail alone or together with the scruff of the neck when positioning on the grid, be aware of doing it smoothly without pressing down upon the grid.
      2. Keeping the torso of the mouse parallel with the grid, pull gently the animal backwards away from the grid by the tail (pulling along the axis of the GSM). The speed has to be slow enough to let the mouse to develop a resistance against the pulling force.
      3. Record the number (peak force) that is displayed on the screen of the GSM once the mouse releases the grid.


        Figure 5. Whole-limbs grip strength measurement

    6. Weigh the mouse.
    7. Return the mouse to its cage.
    8. Clean the grid with 70% ethanol.
    9. Tare (zero) the GSM and proceed with the next subject. Each mouse should be tested several times (3-5 times) with at least 1 min resting period between each test. 

Data analysis

  1. Treadmill exhaustion test
    1. Exercise capacity is commonly evaluated by comparison of both speed and distance values between the animals of interest and their controls, and plotted on a bar graph (Bi et al., 2016).
    2. Other parameters such as work and power can additionally be used (Nie et al., 2016). Work and power are calculated as follows:
      Work (J) = body mass (kg) x gravity (9.81 m/sec2) x vertical speed (m/sec x angle) x time (sec)
      Power (W) = work (J)/time (sec)

  2. Whole-limb grip strength assay
    1. The average force (gripping strength) is used for comparison between experimental groups. Sometimes force measurements are not accurate since the animals can release very quickly without exert any resistance or they can have grasp problems. Therefore, it is recommended to use the mean of the best recorded values for data analysis. The results are plotted on a bar graph (Figures 6 and 7A).


      Figure 6. Gripping strength measurement result of limbs from MLC-N1ICD mice and littermate controls. Each mouse was tested three times (n = 3). The average strength was defined as gripping strength. Statistical analysis was conducted with Student’s t-test with two-tail distribution. **P < 0.01. Bar graphs indicate mean SEM (Adapted from Bi et al., 2016).

    2. It is also common to use the ‘normalized grip force’ for data analysis. This value is obtained by dividing the grip strength mean value with the body weight of each mouse (Figure 7B).


      Figure 7. Graphical representation of Force (A) and Normalized force (B) of 3-month old mutant mice versus littermate controls. Each mouse was tested four times. Data are presented as means ± SE (n = 7).

Notes

  1. General
    1. Environmental variables such as light, noise, humidity or temperature, as well as testing time (morning/afternoon) should be kept constant and at appropriate levels for the animals.

  2. Treadmill exhaustion test
    1. Training sessions facilitate the animals to become familiar with the apparatus and the test conditions, minimizing the psychological stress and increasing their performance in the task. We recommend using an acclimatizing period of 3 to 10 days. Longer training periods could reduce the willingness of the mice to perform the task and blunt the physiological, molecular and biochemical responses to exercise.
    2. Parameters such as the speed or the duration of the test can be manipulated, resulting in different protocols depending on the objectives to be reached. For example, the effects of aerobic exercise can be evaluated by exercising the animals for 60 min at 14 m/min on a 10% grade, 5 day/week, for 6 weeks (Nie et al., 2016). The modification on the angle of the treadmill would enable the study of the outcomes of uphill (incline-slope, concentric) and downhill (decline-slope, eccentric) running.
    3. Because this test is a form of forced exercise, it usually requires aversive stimuli to keep the animal running. Here, we used electric shock as a noxious stimuli, but different methods (e.g., air puffs or gently encouragement them by using a tongue depressor) can be used. Also, it is important to consider that genetic background, strains, clinical condition, and other intrinsic variables may influence the sensitivity and response of the animal to the stimulus, requiring and adjustment of the intensity of the stimulus.
    4. Physical exercise can exacerbate the clinical condition of some animal models–like mdx mice–especially during the test, where the animals are exposed to high speeds for long periods of time. Animal models with a weak physical condition may require milder test conditions (using lower uphill slopes and reducing the rate of speed increments, for example).

  3. Whole-limb grip strength assay
    1. Besides environmental factors, it is also important to keep the same operator for all experimental groups under study in order to decrease inter-subject variability (preferably in a blinded fashion).
    2. Check the toes of the mice to make sure there are no visible wounds on them before test.
    3. This grip test is used to measure the muscle strength of combined forelimbs and hind limbs. The same procedure can be used to test the forelimbs strength alone, allowing the mouse to grasp the grid only with the forelimbs.

Acknowledgments

This protocol has been adapted from our previous work published in Elife (Bi et al., 2016) and Cell Reports (Yue et al., 2016) and partially supported by a grant from United States National Institutes of Health to SK (1R01AR071649). Beatriz Castro acknowledges support from the Alfonso Martin Escudero Foundation.

References

  1. Benchaouir, R., Meregalli, M., Farini, A., D'Antona, G., Belicchi, M., Goyenvalle, A., Battistelli, M., Bresolin, N., Bottinelli, R., Garcia, L. and Torrente, Y. (2007). Restoration of human dystrophin following transplantation of exon-skipping-engineered DMD patient stem cells into dystrophic mice. Cell Stem Cell 1(6): 646-657.
  2. Bi, P., Yue, F., Sato, Y., Wirbisky, S., Liu, W., Shan, T., Wen, Y., Zhou, D., Freeman, J. and Kuang, S. (2016). Stage-specific effects of Notch activation during skeletal myogenesis. Elife 5.
  3. Nie, Y., Sato, Y., Wang, C., Yue, F., Kuang, S. and Gavin, T. P. (2016). Impaired exercise tolerance, mitochondrial biogenesis, and muscle fiber maintenance in miR-133a-deficient mice. FASEB J 30(11): 3745-3758.
  4. Puzzo, D., Raiteri, R., Castaldo, C., Capasso, R., Pagano, E., Tedesco, M., Gulisano, W., Drozd, L., Lippiello, P., Palmeri, A., Scotto, P. and Miniaci, M. C. (2016). CL316,243, a β3-adrenergic receptor agonist, induces muscle hypertrophy and increased strength. Sci Rep 5: 37504.
  5. Waning, D. L., Mohammad, K. S., Reiken, S., Xie, W., Andersson, D. C., John, S., Chiechi, A., Wright, L. E., Umanskaya, A., Niewolna, M., Trivedi, T., Charkhzarrin, S., Khatiwada, P., Wronska, A., Haynes, A., Benassi, M. S., Witzmann, F. A., Zhen, G., Wang, X., Cao, X., Roodman, G. D., Marks, A. R. and Guise, T. A. (2015). Excess TGF-β mediates muscle weakness associated with bone metastases in mice. Nat Med 21(11): 1262-1271.
  6. Yue, F., Bi, P., Wang, C., Li, J., Liu, X. and Kuang, S. (2016). Conditional loss of pten in myogenic progenitors leads to postnatal skeletal muscle hypertrophy but age-dependent exhaustion of satellite cells. Cell Rep 17(9): 2340-2353.

简介

体内肌肉功能测试已经成为肌肉表现的主要表型分析的极大兴趣。 该方案提供了详细的步骤,用于执行跑步机疲劳试验和全肢牵引强度测定,这两种方法通常用于神经肌肉研究领域。
【背景】肌肉疾病通常会导致骨骼肌功能的改变。因此,可以评估肌肉性能的非侵入性体内测试作为主要的表型筛选具有相当大的价值。在这里,我们描述如何进行跑步机疲劳试验,评估运动能力和耐力,以及测量肌肉力量的肢体力量测定。在跑步机疲劳试验中,老鼠被迫以逐渐增加的速度在输送带上运行而耗尽。肢体握力测定使用由鼠标掌握的水平抓地力来测量使鼠标释放所需的最大力。这些测试可以轻松定制,以评估不同情况下的肌肉性能,例如治疗干预或再生后(Benchaouir等,2007; Puzzo等,2016),或研究特定基因对肌肉病理病理学的潜在作用Waning et al。,2015; Bi et al。,2016; Yue et al。,2016)。

关键字:疲劳测试, 握力, 小鼠, 肌肉, 跑步机

材料和试剂

  1. 记录表
  2. 适当的小鼠应变和住房设施
  3. 乙醇(70%)或消毒剂擦拭液,洗涤剂和水的温和溶液

设备

  1. 跑步机疲劳试验
    1. 计时器
    2. 塑料托盘
    3. 跑步机系统:3/6跑步机和跑步机控制器(Columbus Instruments,型号:Exer 3/6)(图1)
    4. 计算机和软件由制造商提供


      图1.跑步机系统和部件

  2. 全肢握力测定
    1. 握力仪(哥伦布仪器,型号:1027SM带单传感器的握力仪)。该装置包括连接到力传感器,数字显示器(AMETEK,Chatillon,型号:DFE2-002)的网格和升高它的基座(图2)
    2. 比例


      图2.握力强度计

软件

  1. 跑步机软件(Columbus Instruments,OH,USA)

程序

  1. 跑步机疲劳试验
    1. 训练
      1. 将跑步机设置为所需的倾斜角或偏角。在该仪器中,倾斜角度由弹簧销在倾斜杆孔中的位置决定。通常使用上坡倾斜度(10%的坡度)进行该测试(Bi等人,2016; Nie等人,2016; Yue等人,/em>。,2016)。与运动在平坦的表面上相比,上坡跑步涉及同心肌收缩并增加动物的肌肉功能,导致更快的疲劳。下坡跑步也可用于检查偏心肌收缩
      2. 在仪器下方放置塑料托盘,以收集在测试过程中可能产生的粪便和尿液。
      3. 将车道分隔线插入跑步机的槽中。
      4. 打开跑步机控制器。
      5. 调整电击频率和强度(图3A)。在该装置中,电刺激是脉冲(200毫秒/脉冲)的电流,脉冲重复频率可调(每秒1,2或3次,Hz)和强度(分别为3Hz,1.22mA)。 br />
      6. 将小鼠放在跑步机皮带上,盖上盖子。
      7. 通过将每个切换开关设置为网格(刺激指示器将开始闪烁),为每条线路打开震动网格。
      8. 使用位于跑步机控制器中的"速度"旋钮将皮带速度调整到10米/分钟。将"跑步机皮带"拨动开关设置为"运行"(图3B)。


        图3.使用跑步机控制器的电击刺激(A)和速度(B)调整

      9. 启动计时器让老鼠跑5分钟。
      10. 之后,将"跑步机皮带"切换回"停止"
      11. 禁止所有车道的冲击刺激。
      12. 移除动物并将每只老鼠返回其笼子。
      13. 用70%乙醇清洁跑步机皮带和网格,如果需要训练其他小鼠,请重复步骤A1f至A1l。
      14. 关闭机器。
      15. 清洗粪便收集盘和车道分隔线。
      16. 在测试前连续3天重复训练。
    2. 测试
      1. 执行上一节的步骤A1a到A1e。
      2. 打开电脑并启动跑步机软件。如下设置新的实验:
        1. 选择"实验>>从主菜单运行。
        2. 点击窗口顶部的"配置文件模式"选项卡。
        3. 使用电脑鼠标选择文本框并输入相应的参数(参见表1,图4A)。在该测试中,速度最初设定为10m/min,持续5分钟,并且每2分钟增加2m/min,达到最大速度为46m/min(Bi等人, em>。,2016)。


          图4.跑步机软件。 A.创建配置文件。通过使用计算机鼠标选择文本(白色)框并手动输入相应的参数,创建跑步机运动配置文件;点击"添加周期"可以添加更多的步骤。此配置文件可以保存并用于以后测试其他鼠标。为此,请在配置文件模式屏幕中单击"加载",然后选择保存的文件。 B.运行实验。自动生成图形表示,以显示整个配置文件的相对速度和时间。图形中的垂直红色条指出当前位置,而配置文件表的步骤列中的箭头标示当前正在使用的步骤。步骤时间:通知当前步骤剩余时间; Spd(m/m):报告跑步机皮带的当前速度; Dist Tr(m):报告跑步机皮带移动的总距离。

          表1.跑步机疲劳测试步骤


      3. 将"跑步机皮带"拨动开关设置为"运行"并启用触电。
      4. 点击"开始"按钮。将打开"保存实验数据文件"窗口(另存为.csv文件)。
      5. 将跑步机皮带上的小鼠装入分开的车道,然后点击"确定"
      6. 运行实验,直到老鼠耗尽或达到最大速度。  
        1. 当鼠标耗尽时,记下屏幕上显示的时间,速度和距离(见图4B),并关闭其通道的震动网格。从跑步机上取下鼠标。
          有不同的方法来定义疲劳,并且在整个实验中必须使用相同的标准。例如,耗尽可以被定义为尽管机械刺激,动物在跑步机上运行10秒不能运行(Bi等人,2016; Yue等人, 。,2016)
        2. 当跑步机上没有小鼠停留或达到最大速度时,停止实验并关闭震动网格。
      7. 测试另外的小鼠用70%酒精清洁跑步机和格子,并重复上述步骤。 (在配置文件模式屏幕中单击"加载",然后选择先前生成的保存文件,以免手动重新输入所有数据,然后单击"开始")。在上一次训练之后的第二天,每只老鼠都被测试一次。我们建议至少使用五只动物,以确保高统计能力。由于小鼠的性别,年龄和遗传背景的潜在差异,该测试所需的动物数量的计算应通过功率分析进行。

  2. 全肢握力测定
    1. 将小鼠放在测试室中10分钟以适应(在此期间离开房间)。
    2. 将力量计放在牢固的平坦表面上。
    3. 将电网连接到数字量规,并用70%乙醇或消毒剂擦拭清洁。
    4. 设置握力计(GSM):
      1. 打开GSM。
      2. 在"模式"选项的下方按底部选择峰值张力(T-PK)模式(这显示了由于远离GSM而被施加到GSM的峰值力)。按"主页"返回主屏幕。
      3. 按"单位"底部选择力单位(例如,,Newton,N)
      4. 按"零"以重新去除GSM。
    5. 测试动物(图5):
      1. 从笼子中取出要测试的鼠标,并将其放在网格顶部。让鼠标抓住所有四只爪子的网格。
        当定位在网格上时,鼠标可以单独或与脖子上的尾巴一起被保持,要注意在不压下网格的情况下顺利进行。
      2. 保持鼠标的躯干与网格平行,轻轻地将动物从尾巴(沿着GSM的轴线)向后远离网格。速度必须足够慢,以使鼠标产生抵抗拉力的阻力。
      3. 记录鼠标释放网格后显示在GSM屏幕上的数字(峰值力)。


        图5.全肢握力测量

    6. 称重鼠标。
    7. 将鼠标移回笼子。
    8. 用70%乙醇清洁电网。
    9. 去皮重(零)GSM,并继续下一个主题。每只小鼠应在每次测试之间至少休息一个小时(3-5次)进行测试。 

数据分析

  1. 跑步机疲劳试验
    1. 运动能力通常通过比较感兴趣的动物与其对照之间的速度和距离值之间的平均值来评估,并绘制在条形图上(Bi等人,2016)。
    2. 另外还可以使用诸如工作和功率的其它参数(Nie等人,2016)。工作和权力计算如下:
      工作(J)=身体质量(kg)x重力(9.81 m/sec 2 )x垂直速度(m/sec x角)x时间(秒)
      功率(W)=工作(J)/时间(秒)

  2. 全肢握力测定
    1. 平均力(夹持强度)用于实验组之间的比较。有时力测量不准确,因为动物可以非常快地释放,而不施加任何阻力,或者他们可以掌握问题。因此,建议使用最佳记录值的平均值进行数据分析。结果绘制在条形图上(图6和7A)

      图6.来自MLC-N1ICD小鼠和同窝出生对照的四肢的夹持力测量结果每只小鼠测试三次(n = 3)。平均强度定义为夹紧强度。统计分析是用双尾分布的Student's 测试进行的。 ** 0.01。条形图表示平均SEM(从Bi等人,2016改编)。

    2. 使用"归一化夹持力"进行数据分析也很常见。该值通过将握力强度平均值与每只小鼠的体重相除(图7B)获得。


      图7. 3个月大的突变体小鼠与同窝出生对照的力(A)和归一化力(B)的图形表示。每只小鼠被测试四次。数据表示为±SE(n = 7)。

笔记

  1. 一般
    1. 环境变量如光,噪音,湿度或温度,以及测试时间(早/午))应保持不变,并保持适当的水平。
  2. 跑步机疲劳试验
    1. 培训课程有助于动物熟悉设备和测试条件,最大限度地减少心理压力并提高其在任务中的表现。我们建议您使用3至10天的适应环境。更长的训练时间可能会降低小鼠执行任务的意愿,并使生理,分子和生物化学反应钝化。
    2. 可以操纵诸如速度或测试持续时间的参数,导致不同的协议取决于要达到的目标。例如,有氧运动的效果可以通过以10分钟等级,5天/周,14分钟/分钟的动物运动60分钟,评估6周(Nie等人, 2016)。跑步机角度的修改将能够研究上坡(斜坡,同心)和下坡(下坡,偏心)运行的结果。
    3. 因为这种测试是强制运动的一种形式,它通常需要厌恶的刺激来保持动物的运行。在这里,我们使用电击作为有害的刺激,但是可以使用不同的方法(例如,吹气或通过使用舌头按压器轻轻地鼓励它们)。此外,重要的是考虑遗传背景,菌株,临床状况和其他内在变量可能会影响动物对刺激的敏感性和反应,需要和调整刺激强度。
    4. 体育运动可以加剧一些动物模型(如mdx小鼠)的临床状况,特别是在测试期间,长期暴露于高速的动物。身体状况较差的动物模型可能需要更温和的测试条件(例如使用较低的上坡和降低速度增量的速度)。

  3. 全肢握力测定
    1. 除了环境因素外,为研究所有实验组保持相同的操作者也是重要的,以减少受试者间的变异性(最好是以盲目的方式)。
    2. 检查老鼠的脚趾,以确保在测试前没有可见的伤口。
    3. 该夹持测试用于测量前肢和后肢组合的肌肉力量。可以使用相同的步骤来测试前肢的强度,使鼠标只能用前肢掌握网格。

致谢

该协议已经从我们以前在Elife(Bi等人,2016)发表的工作和Cell Reports(Yue等人,2016)中进行了改编,并且部分地被a授予美国国立卫生研究院SK(1R01AR071649)。 Beatriz Castro承认阿方索马丁埃斯库德罗基金会的支持。

参考文献

  1. Benchaouir,R.,Meregalli,M.,Farini,A.,D'Antona,G.,Belicchi,M.,Goyenvalle,A.,Battistelli,M.,Bresolin,N.,Bottinelli,R.,Garcia,L 。和Torrente,Y。(2007)。  恢复移植外显子设计的DMD患者干细胞进入营养不良小鼠后的人类肌营养不良蛋白。细胞干细胞 1(6):646-657。
  2. Bi,P.,Yue,F.,Sato,Y.,Wirbisky,S.,Liu,W.,Shan,T.,Wen,Y.,Zhou,D.,Freeman,J.and Kuang,S。 2016)。骨骼中Notch激活的阶段特异性效应myogenesis。 Elife 5.
  3. Nie,Y.,Sato,Y.,Wang,C.,Yue,F.,Kuang,S.and Gavin,TP(2016)。  在miR-133a缺陷小鼠中受损的运动耐力,线粒体生物发生和肌肉纤维维持。 FASEB J 30(11):3745-3758。
  4. Puzzo,D.,Raiteri,R.,Castaldo,C.,Capasso,R.,Pagano,E.,Tedesco,M.,Gulisano,W.,Drozd,L.,Lippiello,P.,Palmeri, Scotto,P.和Miniaci,MC(2016)。  CL316,243,β3肾上腺素能受体激动剂,诱导肌肉肥大和增加的力量。 5:37504.
  5. Waning,DL,Mohammad,KS,Reiken,S.,Xie,W.,Andersson,DC,John,S.,Chiechi,A.,Wright,LE,Umanskaya,A.,Niewolna,M.,Trivedi, ,Charkhzarrin,S.,Khatiwada,P.,Wronska,A.,Haynes,A.,Benassi,MS,Witzmann,FA,Zhen,G.,Wang,X.,Cao,X.,Roodman,GD,Marks, AR和Guise,TA(2015)。多余的TGF- β介导与小鼠骨转移相关的肌肉无力。 21(11):1262-1271。
  6. Yue,F.,Bi,P.,Wang,C.,Li,J.,Liu,X.and Kuang,S。(2016)。  造血祖细胞中pten的有条件损失导致产后骨骼肌肥大,但是卫星细胞的年龄依赖性耗尽。 Cell Rep 17(9):2340-2353。
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Copyright Castro and Kuang. This article is distributed under the terms of the Creative Commons Attribution License (CC BY 4.0).
引用: Readers should cite both the Bio-protocol article and the original research article where this protocol was used:
  1. Castro, B. and Kuang, S. (2017). Evaluation of Muscle Performance in Mice by Treadmill Exhaustion Test and Whole-limb Grip Strength Assay. Bio-protocol 7(8): e2237. DOI: 10.21769/BioProtoc.2237.
  2. Bi, P., Yue, F., Sato, Y., Wirbisky, S., Liu, W., Shan, T., Wen, Y., Zhou, D., Freeman, J. and Kuang, S. (2016). Stage-specific effects of Notch activation during skeletal myogenesis. Elife 5.
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