The Effects of Antioxidants and Pulsed Magnetic Fields on Slow and Fast Skeletal Muscle Atrophy Induced by Streptozotocin: A Preclinical Study

Figure 9

Effects of antioxidants and PMF on skeletal muscle biomechanical parameters, fatigue, and body/muscle weight in diabetic rats. (a) The maximum isometric contraction forces, measured in grams of force (g-force), generated by the soleus and extensor digitorum longus (EDL) muscles in response to single-twitch stimulation were recorded using a square wave pulse of 0.5 ms duration and a frequency of 1 Hz, with a stimulation voltage of 15-20 V. (b) A representative diagram of the isometric single-twitch contractions was illustrated to compare the force generation capacity of the soleus and EDL muscles between the diabetic (DM-soleus and DM-EDL) and control (C-soleus and C-EDL) groups. (c) The time from the onset of contraction to the peak force generation (time to peak (TTP)) was measured in milliseconds (ms). (d) The time from the peak of contraction to the end of the contraction (relaxation time (RT)) was also measured in ms. (e) The maximum tetanic contraction forces, measured in g-force, generated by the soleus and EDL muscles in response to high-frequency stimulation were recorded using a square wave pulse of 0.5 ms duration and a frequency of 100 Hz, with a stimulation voltage of 15-20 V. (f) A representative diagram of the tetanic contractions was generated to compare the force generation capacity of the soleus and EDL muscles between the diabetic (DM-soleus and DM-EDL) and control (C-soleus and C-EDL) groups. (g) Isometric contraction forces, measured in g-force, were recorded at different frequencies of stimulation, ranging from 1 to 100 Hz, using square wave pulses of 0.5 ms duration. (h) The distance covered by the rats before signs of fatigue appeared was recorded in meters (m). (i) Fatigue time was measured in minutes (min) using a treadmill test performed once a week with 5 randomly selected rats from each group. The notation “ns” indicates nonsignificant differences () between groups, “χ” indicates significant differences () between groups, “β” indicates significant differences () from DM+PMF, “” indicates significant differences () from DM, and “” indicates significant differences () from C. All data were expressed as , and values were calculated using one-way ANOVA with the Tukey post hoc test for multiple comparisons.

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