Regenerating skeletal muscle cells express insulin-like growth factor I.
The expression of the trophic peptide insulin-like growth factor I (IGF-I; somatomedin C) was investigated in the regenerating soleus muscle of mice after injury by the snake venom taipoxin. No specific IGF-I immunoreactivity was observed in muscle cells during control conditions. Within 2 days after taipoxin injection, IGF-I immunoreactivity could be demonstrated in activated satellite cells. Myoblasts and myotubes expressed high IGF-I immunoreactivity. The IGF-I immunoreactivity was strictly cytoplasmatic and obviously associated with polyribosomes. No vesicular or membraneous IGF-I immunoreactivity could be demonstrated. It is concluded that IGF-I is synthesized in myogenic cells during skeletal muscle regeneration. It is suggested that IGF-I exerts its effects on skeletal muscle mainly by autocrine mechanisms.
Jennische
E
E
Hansson
H A
HA
D000818:Animals; D004546:Elapid Venoms / Q000494:pharmacology*; D005260:Female; D005455:Fluorescent Antibody Technique; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D009132:Muscles / Q000166:cytology / Q000378:metabolism*; D009466:Neuromuscular Blocking Agents / Q000494:pharmacology*; D012038:Regeneration / Q000187:drug effects*; D013002:Somatomedins / Q000378:metabolism*
D004546:Elapid Venoms; D009466:Neuromuscular Blocking Agents; D013002:Somatomedins; C015523:taipoxin; D007334:Insulin-Like Growth Factor I