Influence of epidermal growth factor and gonadotrophin on the in vitro maturation of human oocytes

Reproductive Medical Center, Shandong Provincial Hospital, Shandong University, Jinan, Shandong 250021, China.
Zhonghua nan ke xue = National journal of andrology 05/2004; 10(4):257-9, 262.
Source: PubMed


To study the effect of epidermal growth factor(EGF) and different concentrations of gonadotrophin (Gn) on the in vitro maturation of human oocytes.
EGF was added to the vitro culture medium in order to observe the effect of Gn combined with or without EGF on the result of in vitro maturation. The concentrations of hCG and FSH were changed respectively to observe the difference between the results.
Adding EGF to the culture medium improved the maturation rate of oocyte significantly (P < 0.05). There was no difference between the results with different concentrations of hCG and FSH in the culture medium.
EGF can improve the results of the in vitro maturation of human oocytes by increasing the maturation rate significantly. Increasing the concentration of Gn does not influence the results of in vitro maturation.

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    • "There are several formulas for human IVM but, with few exception [16], they all contain serum, and efforts to produce an optimal medium, and preferably chemically-defined, have been thwarted by the lack of research material. Culture medium supplemented with steroids and growth factors, including oestradiol, progesterone, EGF, IGF-1 and VEGF, have been reported to improve maturation and developmental competence in various animal species [45-50]. However, optimal conditions probably vary between species and even at different phases of the 36 h incubation period, reflecting the evolving physiological state of the preovulatory follicle. "
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    ABSTRACT: In vitro maturation (IVM) of oocytes followed by fertilization in vitro (IVF) and embryo transfer offers an alternative to conventional IVF treatment that minimises drug administration and avoids ovarian hyperstimulation. However, the technique is less efficient than maturation in vivo. In the present study, a non-human primate model was used to address the hypothesis that the number of oocytes is increased and their nuclear and cytoplasmic maturity after IVM are improved when maturation is initiated in vivo by priming with hCG. Young, adult cynomolgus monkeys were given recombinant human (rh) gonadotropins to stimulate the development of multiple follicles, and oocytes were aspirated 0, 12, 24, or 36 h after injection of an ovulatory dose of rhCG. The nuclear status of oocytes was determined at the time of recovery and after culture for a total elapsed time of 40-44 hours after hCG. Priming with hCG significantly increased the number of oocytes harvested, especially after delaying aspiration for 24 h or longer. Nuclear maturation after the full period in culture was also enhanced by priming: 71.5, 83.6, and 94.6% of oocytes collected at 0, 12, and 24 h hCG had progressed to MII by the end of the culture period, compared to 87.8% of oocytes that were retrieved at 36 h. A large proportion of oocytes reaching the MII stage had either or both abnormal spindles (>40%) and misaligned chromosomes (>60%), judging by immunofluorescence microscopy, but these abnormalities were independent of culture time. The mitochondria were evenly distributed throughout the cytoplasm at all stages of maturation. Importantly, there was no microscopic evidence that the duration of culture had any injurious effects on the cells. In conclusion, the evidence supports this non-human primate as a model for human IVM and the practice of priming with hCG to promote developmental potential.
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