Influence Of Exogenous Insulin-like Growth Factor-1 On Proliferation And Differentiation Of Medial Rectus Satellite Cells

Objective: To observe the changes of myoblast proliferation and differentiation as well as IGF-1 expression after exogenous IGF-1 stimulation on the medial rectus of the strabismus model cats and to discuss about the possibility of strabismus medication.Methods: 27 healthy kittens(4-6w) were selected. Models of external strabismus were constructed through surgical operation and were divided into IGF-1 experiment group(Group A), sterile water control group(Group B) and blank control group(Group C). The experiment group was further divided into Group A1(4 weeks), Group A2(8 weeks) and Group A3(12 weeks) according to the construction time of strabismus models. The other two groups were also separately divided into Group B1, B2, B3 and Group C1, C2, C3 with 3 kittens in each group accordingly. The myoblasts were cultured in vitro after regular injections of medicine into the medial rectus of strabismus models, and the growth curve, fusion rate and IGF-1 m RNA expression changes of myoblasts were observed in each group. To study the relationship between IGF-1 m RNA expression and medical intervent ion time.Results: 1 The growth curve of myoblasts: The cellular proliferation rate and cell amount of Group A were higher than that in Group B and C(P<0.05) and there was no evident difference between Group B and C(P>0.05). 2 Fusion rate: The fusion rate in Group A was higher than that of Group B and C(P<0.05) and there was no evident difference between Group B and C(P>0.05). 3 IGF-1 m RNA expression: The relat ive IGF-1 m RNA expression of myoblasts in Group A was higher than that in Group B and C with signif icant differences(P<0.05), while there was no evident difference between Group B and C(P>0.0 5); the IGF-1 expression in Group A were positively related(r=0.83,P=0.023) while they were negatively related in Group B and C(r=-0.56,-0.55,P=0.034,0.036).Conclusions: 1. Exogenous IGF-1 can strengthen the proliferation, differentiation and IGF-1 expression ability of medial rectus cells in cats with external strabismus. 2. IGF-1 expression in cats with strabismus was positively correlated with Exogenous IGF-1 intervention time...