European Journal of Anatomy

Official Journal of The Spanish Society of Anatomy
Cover Volume 11 - Number 1
Eur J Anat, 11 (1): 37-45 (2007)

Abnormalities in tenectomized muscle fiber repair

Pena Amaro J., Luque E., Jimena I., Noguera F., Castilla S., Vaamonde R.

Department of Morphological Sciences, Faculty of Medicine, University of Córdoba, 14071-Córdoba, Spain; Department of Morphological Sciences, Faculty of Medicine, University of Córdoba, Avda. Menéndez Pidal s/n, 14071 Córdoba, Spain

ABSTRACT Experimental tenotomy induces degenerative changes in muscle fibers, followed by an internal repair process. This study examined the cytoarchitectural changes taking place in muscle fibers due to delayed tension recovery prompted by removal of a segment of tendon. The anterior tibial muscles of Wistar rats were studied using light and electron microscopy at 4, 5 and 6 weeks after tenectomy and compared with the same muscles in controls 4 weeks after tenotomy. Control muscles displayed occasional core-like fibers. Tenectomized muscles, in addition to a larger number of core-like lesions, exhibited myofibrillar disorientation as evidenced by desmin staining and electron microscopy, which enabled identification of ring fibers, snake-coil fibers and occasional lobulated fibers. Whereas core-like lesions tended to disappear, the number of fibers displaying a myofibrillar disorientation increased with the time post-tenectomy. This suggests that extraction of a segment of tendon delays the repair of tenotomy-induced core-like lesions and gives rise to abnormal repair, leading to the formation of ring and snake-coil fibers.

Keywords: desmin, animal experiment, animal model, animal tissue, article, controlled study, cytoarchitecture, electron microscopy, male, microscopy, muscle fibril, muscle injury, muscle regeneration, nonhuman, rat, tendon surgery, tibialis anterior muscle, Wistar rat

European Journal of anatomy
ISSN 2340-311X (Online)