Neuromuscular electrical stimulation decrease atrogenes expresion after anterior cruciate ligament rupture on quadriceps muscle of rats

Abstract

The aim of this study was to evaluate the effects of neuromuscular electrical stimulation (NMES) on quadriceps atrophy in the acute period after anterior cruciate ligament (ACL) rupture. We assessed the mRNA levels of atrogin-1 and MuRF1, and the cross sectional area (CSA) of vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL) muscles. Wistar rats were evaluated after 24h, 48h and 72h of ACL rupture, as follows: Control, Sham (surgery without ACL rupture), ACL (ACL ruptured), SE (sham treated with NMES) and ACLE (ACL treated with NMES). Muscle fiber CSA of VL reduced only in ACL after 72h, while VM decreased in both S and ACL groups after 72h compared to control values (p<0.05). Conversely, NMES increased CSA of VM in both SE and ACLE compared to ACL after 72h. MuRF1 and atrogin-1 mRNA levels increased in all muscles and periods investigated compared to control (p<0,05). Interestingly, NMES decreased the MuRF1 and atrogin-1 mRNA levels in the ACL and S groups in their respective period (p<0,05) as follow: 24h for both VM and VL; 48h for both VL and RF, and in 72h for VM, VL and RF. In conclusion, NMES reduced the accumulation of ubiquitin proteossome pathway genes in the majority of analyzed muscle and minimized the CSA reduction of VM in the acute period after ACL rupture or surgery procedure in quadriceps muscle of rats. JL Durigan has a Post-Doctoral fellowship provided by FAPESP (2008/09408-4).