The Modulation Of Insulin-like Growth Factor 2 In Form-deprivation Myopia Of Chickens

Chapter One Expressions of IGF-1, IGF-2 and their receptors in the posterior retina and choroid of form-deprived chicken eyesObjective To investigate the dynamic expression of insulin-like growth factor (IGF) -1,2 and their receptors in the posterior retina and choroid of chicken eyes induced by form-deprivation and their role in the development of experimental myopia.Methods 36 white health Leghorn chickens of one-day-old were included in the study, which were divided into 2 groups: The right eye served as experimental group, subjected to 7, 14 and 21 days of form deprivation (FD) separately. The contralateral, untreated eyes of chickens served as self-control group. The diopter and the axial eye length of all chickens were measured at the beginning and the three time point mentioned above. The expression of IGF-1, IGF-2 and their receptors were assayed by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR), respectively.Results In experimental group, the myopic diopter was deeper and axial eye length was longer when the period of FD was elongated, In self-control group, the hyperopic diopter decreased and axis extended. Immunohistochemistry showed positive stains of IGF-1, IGF-2 and their receptors in both experimental and self-control groups. All the four indexes expressed in ganglion cell layer, outer nuclear layer, retinal pigment epithelium and choroid. In addition, IGF-1, IGF-2 and IGF-1R can be seen in inner nuclear layer. RT-PCR showed IGF-1 and IGF-1R mRNA expression were increased with the elongation of FD in both...