Expressions Of Insulin-like Growth Factors And Insulin-like Growth Factor-1 Recptor In Human Preimplantation Embryos

In vitro, insulin-like growth factors (IGF) were shown as a promoter of cell cycle by having cells pass through GI period from one cell cycle to another. IGF stimulate the oocyte's mature; take part in the process of mitosis of zygote; increase the synthesis of protein; accelerate the development of embryos; inhibit the apoptosis; promote the growth and implantation of embryos. IGF work through insulin-like growth factor receptor (IGFR) which exists in many human tissues such as liver, endometrium, ovary , adrenal gland et al. Recently, studysshowed that there were IGFR and IGF expressions in preimplantation embryos in different kind of animals. To investigate the expressions of IGF-1R and IGF-lmRNA, IGF-2mRNA in human preimplantation embryos and to explore the effects of IGF on human embryos growth and development , 52 surplus embryos of 2-8cell stages, 4 morula, 4 blastula in IVF-ET were collected and divided into 3 groups(IGF-lR, IGF-lmRNA, IGF-2mRNA) randomly. We detected the expressions of IGF-1R and IGF-lmRNA, IGF-2mRNA in human preimplantation embryos with immunohistochemical ABC technique and in situ hybridization assay respectively. The study was done under the anatomy microscope. According to the intensity of color staining appeared in the cells of embryos , positive or negtive expression was defined.Results1 IGF-1R expression was found in whole 19 human preimplantation from 2-cell to 8-cell stages embryos, and had no obvious variation in intensity of staining from different stages embryos .2 There were IGF-lmRNA and IGF-2mRNA expressionsin some 2-cell stage embryos to blastula. Among the 20 samples of IGF- 1 group, a 8-cell stage embryo, a morula and two blastula were found as positive by the red colour appearance . Among the 21 samples of IGF-2 group, 14 embryos were found as strong or poor positive expressions by the different intensity of red staining. IGF-2mRNA expression in the first grade embryos was higher than that in the second grade. There was significant difference between the two grades of embryos in IGF-2mRNA expression.Conclusion1 IGF-IR expression was found in all human preimplantation from 2-cell to 8-cell stages embryos, and had no obvious variation in intensity of staining from whole embryos .2 The expressions of IGF-1 mRNA and IGF-2mRNA were presented in some different stages of human preimplantation embryos respectively, there was variation in the intensity of staining in positive embryos .3 IGF-2mRNA expression in the the first grade embryos was higher than that in the second grade .There was significant difference between the two grades. The expression ofIGF-2mRNA in the embryos would be a criteria to verify the quality of embryos.4 The quality of embryos and the success of embryo transfer would be improved by adding IGF to IVF-ET culture media.