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Objective To explore the effect of irisin on ovarian insulin resistance in rats with polycystic ovary syndrome (PCOS) and its possible mechanism. Methods Female Sprague Dawley rats of 4 weeks old were randomly divided into the control group, model group, and irisin group, with 15 rats in each group. Rats in the model group and irisin group were injected subcutaneously with DHEA 0. 06 mg/g + 0. 2 m L oil on the back of the neck, and the control group with equal volume of oil subcutaneously on the back of the neck every day, and the injection was continued for 20 days. Starting from day 21, the rats in the irisin group were intraperitoneally injected with recombinant human irisin 100 ng/g daily, and the control group and model group were intraperitoneally injected with the same amount of normal saline daily for 14 consecutive days. The next day after successful modeling, the orbital venous blood was collected, and was centrifuged to collect serum, and the serum insulin was detected by ELISA; at 6 h after the last intervention, blood was collected from abdominal aorta, and then was centrifuged to collect the serum. Serum insulin was detected by ELISA. We extracted both ovaries under aseptic conditions, took the right ovarian and used Western blotting to detect insulin receptor substrate 2 (IRS-2), glucose transporter 4 (Glut4), and phosphatidylinositol 3-kinase (PI3K) p85α subunit protein expression; the left ovarian was taken, and the expression levels of IRS-2, Glut4, PI3K p85α mRNA were detected by RT-qPCR. Results After successful modeling, serum insulin levels in the model group and irisin group were significantly higher than that in the control group (all P ＜ 0. 05); after the last intervention, the serum insulin level of the model group was higher than that of the control group (P ＜ 0. 05), and the serum insulin level of the irisin group was lower than that of the model group (P ＜0. 05); while there was no significant difference in serum insulin level between the irisin group and the control group (P ＞0. 05). Compared with the control group, the relative expression levels of IRS-2, Glut4, PI3K p85α protein and mRNA in the ovarian tissues of the model group and the irisin group decreased (all P ＜ 0. 05); however, the relative expression levels of IRS-2, Glut4, PI3K p85α protein and mRNA were higher than those of the model group (all P ＜ 0. 05). Conclusion Irisin can improve ovarian insulin resistance in PCOS rats probably by increasing ovarian insulin resistance-related signals IRS-2, Glut4, and PI3K p85α. [ABSTRACT FROM AUTHOR]

Objective：To investigate the effect of Irisin on the endometrial function in obese rats. Methods：Female SD rats were treated with high-fat diets to induce obesity, while the normal-control group (n=16) was treated with normal diets. The obese rats were randomly divided into the model-control group (n=16) and the irisin group (n=16). The rats in the irisin group were injected intraperitoneally with recombinant irisin [100 ng/（g· d）×14 days], while the rats in the two control groups were injected with normal saline. Then, female rats in estrus were mated with male rats. Eight rats were sacrificed in each group on the day 5 and day 10 of pregnancy. The pregnancy rate, average number of blastocyst and embryo morphology were observed. The expressions of leukemia inhibitory factor (LIF) and integrin αvβ3 in the implantation sites were determined. Results：The body weight in the irisin group after treatment was significantly lower than that in the model-control group (P=0.035), and the average number of blastocyst in the model-control group were significantly lower than that in the irisin group and the normal-control group (both P＜0.05). The endometrium of the normal-control group was full, and the embryo was well developed. The uterine cavity in the model-control group was large, and the embryonic development was poor. The endometrium of the irisin group was closed, and the embryonic development was well improved. The expression levels of LIF and integrin αvβ3 mRNAs and proteins in the model-control group were significantly lower than those in the normal-control group and the irisin group (all P＜0.05). Conclusions：Irisin can improve the endometrial receptivity of obese rats by increasing the expressions of LIF and integrin αvβ3 in endometrium. [ABSTRACT FROM AUTHOR]