No abstract

Background: It is known that exercise can be one of the causes of muscular damage. In recent times, physiotherapists and medical professionals have been employing PIE techniques to stimulate muscle recovery to improve its performance after the injury. Methods: We pretend to analyze if the PIE technique could reduce muscle damage, inflammation, and pain in the present study. Female Wistar rats were assigned to one of three different groups: control (C), notexin (NOT) and notexin with PIE (NOT+PIE6). We used the PIE technique, based on electrical stimulation with a continuous current of 4 pulses at an intensity of 6 mA for 5 seconds, conveyed to the muscle. The response was tested with motor function tests. Results: In these tests, we could observe an increase in time and foot faults when crossing a beam in the NOT group compared to C group rats. On the other hand, a significant decrease in both variables was detected in the NOT+PIE6 compared to the NOT group. Muscle power was measured with a grip strength test, obtaining far better performances in NOT+PIE6 rats when compared to NOT rats. Moreover, the PIE technique prevented the increase of pro-inflammatory proteins IL-6 and chemokines CCL3, CCL4, and CCL5 with their receptor CCR5, induced by notexin in the quadriceps. At the same time, the study evidenced a decrease in both CCR8 and NF-ᴋB expressions after PIE treatment. On the other hand, we obtained evidence that demonstrated anti-inflammatory properties of the PIE technique, thus being the increase in IL-10 and IL-13 in the NOT+PIE6 group compared to the NOT group. Furthermore, when applying PIE after damage, an increase in anti-inflammatory mediators and reduction of pro-inflammatory mediators, which, overall, promoted muscle regeneration, was observed. Conclusion: These results support the idea that the PIE technique improves muscle recovery after toxic damages, which would justify its employment.