Wagner H, Beller F K, Bröcker W
Geburtshilfe Frauenheilkd. 1977 Feb;37(2):124-8.
The biological activity of 2 Graefenberg rings was tested in vitro by electrone microscopy and X-ray microanalysis. The investigation showed that Graefenberg rings made of silver contain a varying amount of copper. The Graefenberg rings showed dissociation of copper in vitro which probably also occurred in the uterine cavity. The effect of the copper on the endometrium was probably a factor in the good contraceptive effectiveness of the Graefenberg silver ring compared for the silk thread intrauterine pessaries.
通过电子显微镜和X射线微量分析对2个格氏环的生物活性进行了体外测试。研究表明，由银制成的格氏环含有不同量的铜。格氏环在体外显示出铜的解离，这可能也发生在子宫腔内。与丝线宫内节育器相比，铜对子宫内膜的作用可能是格氏银环避孕效果良好的一个因素。
