【Animal modeling】-Research on the curative effect and recurrence of GnRH-a plus estrogen on rat endometriosis model

  Objective: To investigate the therapeutic effect of GnRH-a plus different doses of estrogen on endometriosis and its effect on recurrence.

  Methods: Fifty-one rats established endometriosis models were divided into five groups: control group (n=10), subcutaneously injected with normal saline 1 mg/kg, once in total; study group: back-adding group Ⅰ ( Low-dose estrogen group (n=10), add-back group II (medium-dose estrogen group, n=10), add-back group III (high-dose estrogen group, n=10), and GnRH-a group (n=11). The study group was given subcutaneous injection of leuprolide 1 mg/kg for a total of 1 time, and the back-add group I, II and III were given different doses of estradiol valerate (25 μg/kg, 50 μg/kg) from the second week of administration, respectively. kg, 100 μg/kg) by intragastric administration, and at the same time, the GnRH-a group was intragastrically administered with normal saline, 3 mL per animal, once a day in each study group, for a total of 14 days. At the 4th and 7th week after administration, laparotomy was performed to measure the endometriosis. The volume of the endometriotic foci was taken, the expression of TNF-α and StAR in the endometriotic foci were detected by immunohistochemistry, blood was collected from the orbital canthal venous plexus, and the serum CA125 level was detected by enzyme-linked immunosorbent assay.

  Results: Before treatment, there was no significant difference in the volume of ectopic lesions in each group (P > 0.05). At the 4th week, the study group was significantly smaller than the control group, and the difference was significant (P < 0.05). Weekly, the volume of the anti-addition group II and III increased significantly compared with the anti-addition group I and the GnRH-a group, and the difference was significant (P < 0.05). There was no significant difference in StAR expression (P > 0.05). At the 4th week, the expression of TNF-α and StAR in the study group was significantly lower than that in the control group, and the difference was significant (P < 0.05). The expression of TNF-α and StAR was higher than that in the anti-addition group I and GnRH-a group, and the difference was significant (P < 0.05). . In the 4th week, the serum CA125 level of the study group was lower than that of the control group, and the difference was significant (P < 0.05). In the 7th week, the serum CA125 levels of the anti-addition group II and III were higher than those of the anti-addition group I and GnRH-a group, and the difference was significant. Significant (P < 0.05).

  Conclusion: GnRH-a reverse addition of low dose estrogen has a good effect on rat endometriosis model, reverse addition of medium and high dose estrogen may promote endometriosis in rats by inducing TNF-α and StAR recurrence.