Abstract
Skeletal muscle phenotype alterations following hemiparetic stroke contribute to disabilities associated with stroke. The phenotypic response following stroke is undefined. This investigation examined the myosin heavy chain (MHC) composition of the vastus lateralis (VL) of stroke survivors in paretic (P) and nonparetic (NP) muscle. Protein obtained from VL of 10 stroke survivors was isolated and purified, and MHC gel electrophoresis was performed. The MHC bands were quantified, and a paired sample two-tailed T test with significance set at p ≤ 0.05 was performed. MHC I expression was significantly less in P versus NP VL (.93 vs. 1.00 arbitrary units [AU]). Significantly more IIx MHC was found in the P versus NP VL (1.33 vs. 1.0). No significant differences in type IIa MHC (1.07 P vs. 1.00 NP) were found. These changes in MHC composition suggest an alteration in muscle function due to stroke or the altered activity patterns of muscle following stroke.
Funding was provided by the Department of Veterans Affairs Medical Center Baltimore Stroke Research Enhancement Program; Department of Veterans Affairs Medical Center Baltimore Geriatric Research, Education and Clinical Center (GRECC); Department of Veterans Affairs Rehabilitation Research and Development Baltimore Center of Excellence in Exercise and Robotics Rehabilitation (B3688R); Department of Veterans Affairs Merit Review (Inflammatory Abnormalities in Muscle After Stroke: Effects of Exercise); NIA Claude D. Pepper Older Americans Independence Center (P30-AG028747); and NIA T32 University of Maryland training program (T32 AG 000219).