Objective The aim of this study was to evaluate adaptations in soleus and tibialis anterior muscles in a rat model 4 wks after hemorrhagic stroke. Design Young adult Sprague Dawley rats were randomly assigned to two groups: stroke and control, with eight soleus and eight tibialis anterior muscles per group. Hemorrhagic stroke was induced in the right caudoputamen of the stroke rats. Control rats had no intervention. Neurologic status was evaluated in both groups before stroke and 4 wks after stroke. Muscles were harvested after poststroke neurologic testing. Muscle fiber types and cross-sectional areas were determined in soleus and tibialis anterior using immunohistochemical labeling for myosin heavy chain. Results No generalized fiber atrophy was found in any of the muscles. Fiber types shifted from faster to slower in the tibialis anterior of the stroke group, but no fiber type shifts occurred in the soleus muscles of stroke animals. Conclusions Because slower myosin heavy chain fiber types are associated with weaker contractile force and slower contractile speed, this faster to slower fiber type shift in tibialis anterior muscles may contribute to weaker and slower muscle contraction in this muscle after stroke. This finding may indicate potential therapeutic benefit from treatments known to influence fiber type plasticity.
|Original language||English (US)|
|Number of pages||9|
|Journal||American Journal of Physical Medicine and Rehabilitation|
|State||Published - Apr 1 2019|
Bibliographical noteFunding Information:
From the Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, Minnesota (LMS); Department of Neu-rosurgery, University of Minnesota, Minneapolis, Minnesota (WCL); and De-partment of Physical Therapy and Athletic Training, Boston University, Boston, Massachusetts (LVT). All correspondence should be addressed to: LeAnn M. Snow, MD, PhD, MMC 388, 420 Delaware St. SE, Minneapolis, MN 55455. This study was supported by NIH-K08HD049459. The results of this study have not been previously presented at any professional association meeting. Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0894-9115 DOI: 10.1097/PHM.0000000000001062
- Skeletal Muscle