Effects of IL-6 on the development of zygote in mice after controlled ovarian hyperstimulation / 解放军医学杂志

ABSTRACT

ObjectiveTo study the effect of IL-6 on the development of zygotes of mice after controlled ovarian hyperstimulation. Methods The present experiment included three parts a) Addition of IL-6 80 female ICR mice were divided into 7 groups by random number table including 6 groups of superovulation (10 each) and a group of natural ovulation cycle (n=20). According to addition of IL-6 in different concentration to culture media, the superovulated ICR mice were divided into superovulation control group (0pg/ml IL-6 group), 1pg/ml IL-6 group, 5pg/ml IL-6 group, 10pg/ml IL-6 group, 25pg/ml IL-6 group, and 50pg/ml IL-6 group, with ICR mice in natural ovulation cycle served as control. b) Addition of IL-6 receptor antibody (RA) 90 female ICR mice were divided into 7 groups according to the random number table, including 5 groups of superovulation (10 each) on the basis of addition of different concentrations IL-6 and IL-6 RA to culture media (0pg/ml IL-6+RA groups, 1pg/ml IL-6+RA group, 5pg/ml IL-6+RA group, 10pg/ml IL-6+RA group, 25pg/ml IL-6+RA group), and 2 groups of normal natural cycle (20 each), including control group and the control group+IL-6 RA (100pg/ml) group. Mice in normal control group conceived naturally while those in superovulation group conceived after superovulation. The zygotes were collected and cultured in vitro for 1 day till the formation of 2-cell embryos, then the rate of 2-cell formation was observed under microscope. Experiments of each group were repeated three times. c) Immunofluorescence identification 10 female ICR mice were divided into control group and superovulation group (5 each) by random number table method. The expressions of IL-6 in zygotes were determined with confocal immunofluorescence method. Results IL-6 addition experiment the rate of 2-cell formation was significantly lower (P<0.05) in superovulated control group, 1pg/ml IL-6, 25pg/ml IL-6 and 50pg/ml IL-6 groups than in control group (P=0.023, P=0.026, P=0.000 and P=0.000, respectively). IL-6 receptor antibody (RA) addition experiment compared with normal control group, the rate of 2-cell formation decreased in superovulation group (P=0.017), so did in other IL-6 RA groups (P=0.000). Immunofluorescence identification the expression of IL-6 in zygote was obviously lower in superovulation group than in control group. Conclusion Controlled superovulation can reduce the expression of IL-6 in zygote, and it may be related to its effect on embryonic development of mice.