Oxidative stress, vitamin E and progestin breakthrough bleeding.

Endometrial bleeding problems can be the major reason for discontinuing progestin-only contraception. In this study the endometrial angiogenic response in Norplant users was found to be lower than in women with normal menstrual cycles. These disturbances in angiogenic response may be caused by oxidant-antioxidant imbalance in the endometrium. The aims of this study were to investigate the effect of progestin only contraceptives on blood concentrations of lipid peroxide and vitamin E, and the effect of vitamin E supplementation on endometrial angiogenic response in vitro. The subjects for this study were Norplant users, depo-medroxyprogesterone acetate (DMPA) users, and controls. Circulating lipid peroxide and vitamin E concentration was measured by routine methodology. Endometrial angiogenic response was assayed using an endothelial cell migration assay. The results showed that the blood concentrations of lipid peroxide from Norplant users with bleeding problems were significantly higher than normal menstrual controls (P < 0.05) and supplementation of vitamin E (in vitro) increased the endometrial angiogenic score. Blood concentrations of lipid peroxide were significantly increased (P < 0.05), and the blood concentrations of vitamin E were significantly decreased (P < 0.05) after 3 months exposure to Norplant or DMPA. The endometrial angiogenic scores in Norplant and DMPA users were significantly lower than in controls (P < 0.02). It is concluded that in progestin-only contraceptive users, higher lipid peroxide and lower vitamin E concentration may cause endometrial cell damage and decrease the endometrial angiogenic response. It is suggested that vitamin E supplementation may counteract these unwanted side-effects.

Benefits of vitamin E supplementation to Norplant users--in vitro and in vivo studies.

Norplant subcutaneous implantation is a contraceptive method used in Indonesia. Endometrial bleeding is one major reason to discontinue the use of Norplant. Angiogenic response in the endometrium of Norplant users was found to be lower than in women with normal menstrual cycle. This disturbance in the angiogenic process may be caused by an imbalance of pro- and antioxidant processes in the endometrium of Norplant users. The aim of this study is to investigate the effect of vitamin E on the endometrial angiogenic activity and to assess the efficacy of vitamin E supplementation in treating endometrial bleeding in Norplant users. Subjects for this study were selected from Norplant users with an exposure of at least 3 months, with endometrial bleeding and recruited on the basis of fully informed consent. TBA reaction was used to measure degradation products of lipid peroxidation. The endometrial angiogenic response was assayed according to Folkman et al. (Folkman et al., 1989. Nature 239, 58-61). Samples from endometrial biopsies were incubated in vitro with vitamin E or placebo before angiogenic measurement. For in vivo supplementation, vitamin E 200 mg/day, or placebo for 10 days/month were given to the subjects with double blind randomisation. The results showed that the blood levels of TBA-reactive substances were significantly higher in Norplant users than in controls. In the endometrium from Norplant users with bleeding problems, in vitro supplementation of vitamin E resulted in a significantly higher angiogenic score than placebo. Although a highly significant reduction of bleeding days in both groups, vitamin E and placebo, was seen during the 2 months of the study, the number of bleeding days was significantly lower in women treated with vitamin E than with placebo.

Endometrial angiogenic response in Norplant users.

The levonorgestrel-releasing subdermal contraceptive implant Norplant is well accepted among Indonesian users, despite the problems with irregular and prolonged menstrual bleeding. Bleeding can be the major reason for women discontinuing their use of Norplant. The causes of endometrial bleeding may include disturbances in endometrial regeneration and angiogenesis. The aim of this study was to investigate endometrial angiogenic activity in Norplant users and to compare it to that in the normal menstrual cycle. The study also aimed to determine the correlation between endometrial angiogenic activity and plasma concentrations of oestradiol, progesterone, sex hormone binding globulin and levonorgestrel, as well as the free levonorgestrel index. The subjects for this study were selected from Norplant users with an exposure of between 3 and 12 months. Endometrial angiogenic response was assayed using an endothelial cell migration assay. Six blood samples to monitor oestradiol and progesterone concentrations were taken during the 2 weeks prior to endometrial biopsy. Samples for the analysis of sex hormone binding globulin and levonorgestrel were taken on the day of biopsy. The results showed that the median score of endometrial angiogenic activity in the 30 women used as controls were significantly higher than the 40 Norplant acceptors (z = -3.80, one tail, P < 0.001). There was no significant correlation between the endothelial migration score and peripheral hormonal concentrations or the free levonorgestrel index in Norplant users. There was no difference in the endometrial angiogenic activity in endometrium with and without bleeding problems. However, it is interesting to note that four Norplant acceptors who had an endothelial cell migration score > or = 1.0 had the lowest free levonorgestrel index.

PIP: A study of 40 Norplant acceptors and 30 controls from Jakarta, Indonesia, demonstrated that use of this contraceptive method reduces angiogenic activity in the endometrium. The endothelial cell migratory activity toward endometrial explants from controls was significantly higher than explants from Norplant users (p 0.001). There was no significant association between the endothelial migration score and peripheral hormonal concentrations or the free levonorgestrel index in Norplant users. Plasma estradiol concentrations in Norplant users fluctuated from 20.00 to 453.54 pg/ml, and there was a nonsignificant trend for lower estradiol concentrations to be associated with amenorrhea. The plasma concentration of levonorgestrel was 0.81 +or- 0.07 nmol/l at 6.20 +or- 0.33 months' duration of Norplant use. There was no difference in the endometrial angiogenic activity in the endometrium on the basis of the presence of prolonged or irregular bleeding/spotting. Of interest was the finding that the 4 Norplant acceptors with an endothelial cell migration score of 1.0 or above had the lowest free levonorgestrel index. This suggests the possibility that the free levonorgestrel index could be used to predict a better endometrial angiogenic response in Norplant users.

Reduced endothelial cell migratory signal production by endometrial explants from women using Norplant contraception.

Bleeding problems can be one of the major reasons for women to discontinue the use of hormonal contraceptives. Causes of endometrial bleeding can include disturbances in endometrial regeneration and angiogenesis. Endothelial cells migrate and proliferate rapidly as part of the angiogenic process under the influence of appropriate stimuli. The aim of this study is to investigate the production of endothelial cell migratory signals by endometrial explants from women receiving Norplant and to compare it to that of those with a normal menstrual cycle. The subjects were selected from Norplant users with an exposure of 3-9 months. The endothelial cell migratory signal production was assayed using the Folkman method (1989), modified by Rogers (1992). Blood serum concentrations of oestradiol, progesterone and sex hormone binding globulin were monitored for 2 weeks prior to endometrial biopsy. Endothelial cell migration toward endometrial explants of 30 women as control and 46 Norplant acceptors was assayed. The results showed that endothelial cell migratory activity toward endometrial explants from the control group was significantly higher than toward those from Norplant acceptors (z = 3.89, P < 0.001). There were no differences between endometrial endothelial cell migratory activities in Norplant acceptors with bleeding or without bleeding problems.

PIP: Researchers examined the production of endothelial cell migratory signals by endometrial explants from 46 Norplant acceptors aged 18-40 and compared it with endothelial cell migratory signals produced by endometrial explants from women using no hormonal contraception or an IUD and having a normal menstrual cycle. The results will provide insight into the role of endothelial cell migration in endometrial bleeding among Norplant acceptors. Both cases and controls attended the Raden Saleh Clinic in Jakarta, Indonesia. Health providers took peripheral blood samples 6 times at 2-3 day intervals before the endometrial biopsy to monitor serum levels of estradiol, progesterone, and sex hormone-binding globulin (SHBG). Laboratory researchers used a three-dimensional collagen matrix culture medium containing dispersed human umbilical vein endothelial cells as modified by Rogers (1992) to conduct the endothelial cell migration assay. Endothelial cell migration toward endometrial explants of the control group was much higher than toward those of the Norplant group (p 0.001). For example, 30 of 46 of the Norplant endometrial explants had a median endothelial cell migratory score of zero compared to 8 of the 30 control biopsies. In fact, only 1 of the control biopsies of the individual 500-cubic-micrometer explants did not respond, while 19 of the like Norplant explants did. In controls, endothelial cell migration was greater in the proliferative phase than in the secretory phases. Endothelial cell migration toward endometrial biopsies of Norplant acceptors with bleeding problems was the same as that toward Norplant acceptors with no bleeding problems. Serum levels of estradiol, progesterone, and SHBG were not associated with endothelial cell migration. These findings do not support the belief that increased angiogenesis in the endometrium of Norplant acceptors is responsible for endometrial bleeding.