[Effect of moxibustion with wheat-grain-sized moxa cones on uterine natural killer cells and deci-dualization in rats with thin endometrium]

Abstract

Objective: To observe the effect of moxibustion at "Shenshu"(BL23) and "Guanyuan" (CV4) on decidua-lization and uterine natural killer cells in rats with thin endometrium, so as to explore its mechanism underlying promotion of embryo implantation.

Methods: Female SD rats were randomly divided into normal control, model and wheat-grain-sized moxa cone moxibustion (moxibustion) groups, with 14 rats in each group. The thin endometrium model was established by bilaterally intrauterine perfusion of 95% ethanol (first) and saline (later) during estrus. For rats of the moxibustion group, the ignited wheat-grain-sized moxa cones were applied to bilateral BL23 and CV4, with 7 moxa cones for each acupoint, once a day, continuously for 3 estrous cycles. Then the male and female rats were raised in the same cage. On the 5^th day of pregnancy, the rats were killed under anesthesia and the uterus tissue was collected for measuring the endometrium thickness and the numbers of blood vessels and glands after H.E. staining, detecting the levels of the proportion of natural killer cells with flow cytometry. After the uterine natural killer cells were sorted by the immunomagnetic bead method, the expression levels of insulin-like growth factor binding protein (IGFBP-1), interferon(INF-γ), tumor necrosis factor(TNF-α), transforming growth factor(TGF-β), interleukin 4(IL-4) and IL-10 mRNAs were detected by using fluorescence quantitative real-time PCR.

Results: Compared with the normal control group, the endometrium thickness, number of glands and blood vessels, and the expression levels of IGFBP-1, TGF-β, IL-4 and IL-10 mRNAs were significantly decreased (P<0.01, P<0.05), while the expression levels of IFN-γ and TNF-α mRNAs were significantly increased (P<0.05，P<0.01) in the model group. In contrast to the model group, the endometrium thickness, number of glands and blood vessels, and the expression levels of IGFBP-1, TGF-β, IL-4 and IL-10 mRNAs were significantly increased (P<0.05, P<0.01), while the expression levels of IFN-γ and TNF-α mRNAs were considerably down-regulated (P<0.05, P<0.01) in the moxibustion group. No significant difference was found among the 3 groups in the proportion of natural killer cells in the endometrium (P>0.05).

Conclusion: Moxibustion of BL23 and CV4 with wheat-grain-sized moxa cones can improve the degree of thin endometrial decidualization, which may be related with its functions in regulating the levels of cytokines secreted from natural killer cells in the uterus.

Keywords: Decidualization; Natural killer cell; Thin endometrium; Wheat-grain-sized moxa cone moxibustion.