Objectives: To evaluate the effects of insulin-like growth factor-I (IGF-I) on the maturation, fertilization, and cleavage of murine oocytes.
Methods: Immature and mature murine oocytes were cultured alone or together with murine spermatozoa in vitro. Various concentrations of IGF-I were added to the media as experimental groups, and was not added as controls. Then the rates of maturation, fertilization and cleavage of murine oocytes were observed, and compared between the 2 groups.
Results: The rates of maturation, fertilization and cleavage of murine oocytes in experimental groups were significantly higher than those in the controls (P < 0.01 or P < 0.05). Unequal blastomeres and cell fragments were observed in both groups, but the differences during the same cultured period were not statistically significant (P > 0.05).
Conclusions: IGF-I could induce murine oocyte maturation, promote its fertilization and cleavage in vitro, and do no harm to the fertilized oocytes and embryos.