Uterine copper distribution in monkeys implanted with copper-carrying intrauterine devices

Chemical and histochemical analyses were carried out on uteri of four monkeys in which plastic IUDs or Cu-IUDs had been implanted for 36 to 43 days. The mean uterine copper content of the plastic-treated animals was 1.1 mug/gm (mean of two), while this value for the Cu-IUD treated monkeys was 1.7 mug/gm. The copper was distributed primarily in the cyclically renewed regions of the endometrium: the luminal fluid, endometrial surface, and superficial lamina propria. The element was localized and was not uniformly distributed in these regions. Copper analyses of plasma, liver, and kidney showed no differences between these two groups. Histopathologic evaluation revealed some areas of edema and increased numbers of neutrophils in plastic-IUD-treated animals. In the Cu-IUD-implanted monkeys, similar changes were observed as was a flattening of the surface epithelium. The endometrium had a loose areolar appearance. The copper elution rate was about 90 mug/day, about twice that observed in women using Cu-IUDs.