Objective: To observe the repairing effects of estrogen and wheat-grain moxibustion on thin-type endometrium in rats and to explore its possible mechanism.
Methods: Forty healthy SPF-grade adult female SD rats were randomly divided into a normal group, a model group, an estrogen group and a moxibustion group according to random number table method, 10 rats in each group. The model of thin-type endometrium was established during estrous period in all the groups except for the normal group. No intervention was given in the normal group. The intragastric administration of 2 mL of 0.9% sodium chloride solution was applied the next day after modeling in the model group. The intragastric administration of 2 mL of estradiol was given the next day after modeling in the estrogen group. The wheat-grain moxibustion was given at "Guanyuan" (CV 4) and "Shenshu" (BL 23) the next day after modeling in the moxibustion group, 7 moxa cones for each acupoint. The treatment in 3 groups was given once a day. After three estrous cycles, the samples were collected during estrous period; the thickness and morphology of endometrium were observed by HE staining; the expressions of vimentin, keratin and vascular endothelial growth factor (VEGF) in endometrium tissue were detected by immunohistochemistry; the expressions of HOXA10 and LIF in endometrium tissue were detected by Western blot.
Results: The endometrial thickness in the model group was significantly thinner than that in the normal group (P<0.01); compared with the model group, the endometrial thickness in the estrogen group and the moxibustion group were increased significantly (P<0.05, P<0.01); the endometrial thickness in the moxibustion group was insignificantly higher than that in the estrogen group (P>0.05). The expressions of keratin, vimentin and VEGF in endometrium in the model group were significantly lower than those in the normal group (P<0.01); compared with the model group, the expressions of keratin, vimentin and VEGF in endometrium in the estrogen group and the moxibustion group were significantly increased (P<0.01). The expressions of keratin, vimentin and VEGF in the moxibustion group were insignificantly higher than those in the estrogen group (P>0.05). The expressions of HOXA10 and LIF in endometrium in the model group were significantly lower than those in the normal group (P<0.01); compared with the model group, the expressions of HOXA10 and LIF in endometrium in the estrogen group and moxibustion group were significantly increased (P<0.05).
Conclusion: The wheat-grain moxibustion could up-regulate the expressions of keratin, vimentin and VEGF in endometrium to improve the endometrial thickness; in addition, it could increase the levels of factors related to endometrial receptivity including HOXA10, LIF, which improves endometrial receptivity and play a repair role.
Keywords: endometrial receptivity; estradiol; thin-type endometrium; wheat-grain moxibustion.