Objective:To observe the expression of IGF1R in muscle satellite cells of normal and cardiotoxin-intoxicated muscle tissues in situ

so as to contribute useful data for further investigation of the molecular mechanism involved in muscle regeneration.Methods:Twelve C57 mice were divided into six groups.In 1st to 6th group

the mice were injected with cardiotoxin(5 μg per mouse) in left quadriceps femoris

while their right quadriceps femoris were left for control without any injection.After the mice were sacrificed at different time-points(1

4 d

1

2

4

6 week)

the quadriceps femoris were isolated.The histological

immunohistochemical analysis and reverse transcription-Polymerase Chain Reaction(RT-PCR) were used to investigate the expression of IGF1R in muscle tissues in situ.Result:HE staining results demonstrated that the muscle tissues experienced the process from muscle injury

repair

to regeneration.The result of immunohistochemistry and RT-PCR showed that there were few expression of IGF1R in muscle satellite cells of normal muscle tissues.Compared with normal tissues

obviously increased expression of IGF1R in 24 hour-group to sixth week-group was found.And

the expression of IGF1R peaked at 2nd week.Conclusion:IGF1R may play an important role in the process of muscle impairment and reparation.