Comparative study of muscle regeneration following cardiotoxin and glycerol injury.
In the present study, we examined muscle regeneration following two types of chemical injuries, cardiotoxin (CTX) and glycerol, in order to compare their effect on the morphological characteristics during muscle regeneration, in addition we studied the structural changes of the intramuscular connective tissue (IMCT) during the regeneration process, by scanning electron microscopy (SEM) after digestion of the cellular elements of the muscle with sodium hydroxide. Tibialis anterior (TA) muscles of adult male mice were injected either with CTX or glycerol. Muscle degeneration was greater in the CTX-injured model than in the glycerol-injured model at day 4 post injection. Muscle regeneration started at day 7 in both the CTX and glycerol models. However, the CTX-injured model showed a higher myotube density and larger myotube diameter than the glycerol-injured model at days 10 and 14 post injection. On other hand, adipocyte infiltration was detected in the glycerol-injured model. In contrast, no adipocytes could be detected in the CTX-injured model. Furthermore, ultrastructural analysis showed a significant difference in myofiber damage and regeneration between the two models. SEM of the IMCT showed a transient increase in endomysial collagen deposition at early stages of regeneration in the CTX-injured model. In contrast, glycerol-injured model showed slight endomysial collagen deposition. Our results suggest that changes in IMCT affect the efficiency of muscle regeneration. Studying the three dimensional structure of IMCT may help clinical therapies to reduce skeletal muscle fibrosis. To our knowledge this is the first time the changes in IMCT following CTX and glycerol injury using SEM-cell maceration technique have been compared.
Laboratory of Basic Veterinary Science, United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Yamaguchi, Japan; Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Tottori, Japan; Department of Anatomy and Embryology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt.
Mohamed A A
MA
Mahdy
Laboratory of Muscle Biology and Meat Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan.
Hsiao Yin
HY
Lei
Laboratory of Muscle Biology and Meat Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan.
Jun-Ichi
J
Wakamatsu
Laboratory of Basic Veterinary Science, United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Yamaguchi, Japan; Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Tottori, Japan.
Yoshinao Z
YZ
Hosaka
Laboratory of Muscle Biology and Meat Science, Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan.
Takanori
T
Nishimura
D017667:Adipocytes / Q000473:pathology; D000818:Animals; D054715:Cardiotoxins / Q000633:toxicity*; D003094:Collagen / Q000378:metabolism; D003238:Connective Tissue / Q000187:drug effects / Q000254:growth & development; D005990:Glycerol / Q000633:toxicity*; D021621:Imaging, Three-Dimensional; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008855:Microscopy, Electron, Scanning; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D018482:Muscle, Skeletal; D009135:Muscular Diseases / Q000139:chemically induced* / Q000473:pathology*; D012038:Regeneration / Q000187:drug effects*; D012972:Sodium Hydroxide / Q000737:chemistry
D054715:Cardiotoxins; D012972:Sodium Hydroxide; D003094:Collagen; D005990:Glycerol
Cardiotoxin; Cell-maceration technique; Glycerol; Intramuscular connective tissue; Muscle regeneration