Motor neurons receive trophic support from the tissues they innervate. One molecule that is important for peripheral motor neurons is glial cell-line derived neurotrophic factor (GDNF). We have previously reported that GDNF is regulated in an activity-dependent manner in skeletal muscle. For this study we examined the short-term effects of passive stretching on the expression of GDNF in skeletal muscle. Extensor digitorum longus (EDL) muscles were removed from 4 week old Sprague Dawley rats and placed in oxygenated tissue baths containing Ringer’s solution. Tissues were passively stretched for 4 hours while their contralateral counterparts remained in baths at resting tension. We found that GDNF protein content significantly decreased after 4 hours of passive stretching. Muscles pre-treated with the acetylcholine receptor antagonist alpha-bungarotoxin and subsequently subjected to passive stretching displayed unaltered GDNF expression. Alpha-bungarotoxin treatment alone had no significant effect on GDNF levels in skeletal muscle in the absence of any stretching. These results indicate that short-term passive stretching decreases GDNF expression and that the effect is mediated through acetylcholine receptor activation.
This work was supported by NIH grant 1R15 AG022908-01A2, the Faculty Research and Creative Activities Support Fund at Western Michigan University, and MSU-KCMS.
WMU ScholarWorks Citation
Peplinski, Nathan G. and Spitsbergen, John M., "Passive Stretching Decreases Glial Cell Line-Derived Neurotrophic Factor Expression in Skeletal Muscle and Is Dependent upon Acetylcholine Receptor Activation" (2006). Biological Sciences Faculty and Graduate Student Research. 6.