Characterization of copper in uterine fluids of patients who use the copper T-380A intrauterine device.
ABSTRACT The copper intrauterine device (IUD) is a highly effective method of contraception that requires the dissolution of the copper into uterine cavity. However, there is little information about the amount and form of copper in the fluid and whether the presence of this element produces any change in the protein concentration.
Twenty-seven women were divided into three groups that had used IUD for about 6 months, 1 year and > or =3 years. The samples were collected during the proliferative phase (Pp), secretory phase (Sp) and menstruation (M). Square-wave anodic stripping voltammetry (SWASV), cyclic voltammetry (CV), high performance liquid chromatography (HPLC) and atomic absorption spectrometry (AAS) were used in this study.
Total copper concentrations were between 3.9 and 19.1 micro g/ml. The mean and standard deviations were as follows: 6 months, 11.4+/-4.7 micro g/ml of copper; 1 year, 11.5+/-7.0 micro g/ml of copper; and 3 years, 6.2+/-1.5 micro g/ml of copper. Total proteins were quantified by measuring the area under the chromatographic peaks. The mean areas obtained with uterine fluid samples from women who used IUDs for 6 months, 1 year and 3 years were 290,013, 538,934 and 201,863 arbitrary units (AU), respectively. The control sample was only 22323.
The amount of copper released from IUD, although high, is in the form of complexes with proteins. IUDs have a constant copper release for at least 6-12 months. Copper(I) was not detected in the fluid. Copper induces a change in the total protein concentration. The amount of copper released and the amount of proteins is slightly larger during the menstrual stage.
- SourceAvailable from: Frank Hills[show abstract] [hide abstract]
ABSTRACT: The precise mechanism of action of the intrauterine contraceptive device (IUCD) is uncertain. In this study we compared the circulating concentrations of a specific endometrial protein, placental protein 14 (PP14), in 62 women with an IUCD and 16 controls. The concentrations of PP14 were substantially lower in IUCD users. There was no difference in the concentrations of another and less specific endometrial protein, insulin-like growth factor binding protein-1 (IGFBP-1). There was no difference in PP14 concentrations between those women with and without intermenstrual bleeding. We conclude that the reduced concentrations of PP14 in IUCD users reflect defective endometrial function in these women, probably related to the contraceptive effect. We propose that the measurement of PP14 might be a means of comparing the efficiency of different devices.Human Reproduction 07/1996; 11(6):1220-2. · 4.67 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: A methodology has been developed to determine the half-wave potentials of organic Cu chelators in seawater and algal culture media from pseudopolarograms obtained by anodic stripping voltammetry. A linear relationship between half-wave potentials determined from the pseudopolarogram, and thermodynamic stability constants was observed for a collection of model ligands that spanned a wide range of stability constants (log K=12–26.5) and included many functional groups likely to be important in copper complexation in seawater. Results suggested that it is possible to determine thermodynamic stability constants from half-wave potentials, as reported previously for Zn and Fe. Pseudopolarograms from culture media of three Cu stressed phytoplankton species showed very different thermodynamic stability constants, indicating the presence of chemically distinct ligands. The cyanobacterium Synechococcus produced at least two strong Cu chelators. One had a thermodynamic stability constant of log K=36.7±3.0 (obtained by extrapolation of the scale) and complexed from 30%–50% of the total Cu. The second was electrochemically inert, even at −1.6 V. The eukaryotic species produced several chelators with stability constants ranging from log K=22.6–39.1. Seawater samples collected from coastal waters showed similar characteristics. These thermodynamic constants are very high relative to model ligands in the literature, which could reflect coordination by specialized biomolecules. Alternatively, the large negative half-wave potentials could be due to Cu(I) complexes (with log K=10–20) or reflect reductive ligand decomposition of kinetically inert Cu(II) complexes.Marine Chemistry 01/1999; 67:219-232. · 3.00 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: The relationship between intrauterine device (IUD) use and risk of endometrial cancer has been analysed in a case-control study conducted in Italy between 1983 and 1992, including 453 patients with histologically confirmed endometrial cancer and 1,451 controls admitted for acute, non-gynaecological, non-hormonal, non-neoplastic conditions to the same network of hospitals where cases had been identified. Two (0.4%) cases versus 36 (2.3%) controls reported ever using an IUD. The corresponding multivariate relative risk was 0.4 (95% CI 0.1-1.0). The results of this study and the few published available epidemiological data suggest a protective role of IUD use on endometrial carcinogenesis, but potential selective mechanisms for IUD utilisation (indication bias) should be carefully considered in the interpretation.British Journal of Cancer 11/1994; 70(4):672-3. · 5.08 Impact Factor