Abordaje integral de la Interrupción Voluntaria del Embarazo: (segunda entrega) / Comprehensive approach to the voluntary interruption of pregnancy: (second issue)

La legalización de la interrupción voluntaria del embarazo ha transformado la práctica médica con respecto a la atención de las pacientes que desean interrumpir la gestación hasta la semana 14 en Argentina. En la primera entrega, el equipo PROFAM compartió su punto de vista a través de una adaptación de su material educativo destinado, sobre todo, a aclarar los aspectos legales que hacen a la práctica cotidiana. En esta entrega se desarrolla en detalle el procedimiento para realizar un aborto farmacológico con misoprostol y mifepristona, así como las generalidades del aspirado manual endouterino. (AU)

The legalization of voluntary termination of pregnancy has transformed medical practice regarding the care of patients who wish to terminate a pregnancy up to 14 weeks in Argentina. In the first issue, the PROFAM team shared its point of view through an adaptation of its educational material aimed, above all, at clarifying the legal aspects of daily practice. In this issue, the procedure to perform a pharmacological abortion with misoprostol and mifepristone is developed in detail, as well as the generalities of manual uterine aspiration technique. (AU)

Analysis of the endometrial transcriptome at the time of implantation in women receiving a single post-ovulatory dose of levonorgestrel or mifepristone

Abstract Background: Levonorgestrel (LNG) is a progesterone receptor agonist used in both regular and emergency hormonal contraception; however, its effects on the endometrium as a contraceptive remain widely unknown and under public debate. Objective: To analyze the effects of LNG or mifepristone (MFP), a progesterone receptor antagonist and also known as RU-486, administered at the time of follicle rupture (FR) on endometrial transcriptome during the receptive period of the menstrual cycle. Methods: Ten volunteers ovulatory women were studied during two menstrual cycles, a control cycle and a consecutively treated cycle; in this last case, women were randomly allocated to two groups of 5 women each, receiving one dose of LNG (1.5 mg) or MFP (50 mg) the day of the FR by ultrasound. Endometrial biopsies were taken 6 days after drug administration and prepared for microarray analysis. Results: Genomic functional analysis in the LNG-treated group showed as activated the bio-functions embryo implantation and decidualization, while these bio-functions in the T-MFP group were predicted as inhibited. Conclusions: The administration of LNG as a hormonal emergency contraceptive resulted in an endometrial gene expression profile associated with receptivity. These results agree on the concept that LNG does not affect endometrial receptivity and/or embryo implantation when used as an emergency contraceptive.

Antiproliferative effect of mifepristone (RU486) on human neuroblastoma cells (SK-N-SH): in vitro and in vivo studies

RU486 (mifepristone), a glucocorticoid and progesterone receptor antagonist, has been reported to exert antiproliferative effects on tumor cells. Experiments were performed to analyze the effects of RU486 on the proliferation of the human neuroblastoma, both in vitro and in vivo, using the human neuroblastoma SK-N-SH cell line. The exposure in vitro of SK-N-SH cells to RU486 revealed a dose-dependent inhibition of 3H-thymidine incorporation due to a rapid but persistent inhibition of MAPKinase activity and ERK phosphorylation. A significant decrease of SK-N-SH cell number was evident after 3, 6, and 9 days of treatment (up to 40% inhibition), without evident cell death. The inhibitory effect exerted by RU486 was not reversed by the treatment of the cells with dexamethasone or progesterone. Moreover, RU486 induced a shift in SK-N-SH cell phenotypes, with an almost complete disappearance of the neuronal-like and a prevalence of the epithelial-like cell subtypes. Finally, the treatment with RU486 of nude mice carrying a SK-N-SH cell xenograft induced a strong inhibition (up to 80%) of tumor growth. These results indicated a clear effect of RU486 on the growth of SK-N-SH neuroblastoma cells that does not seem to be mediated through the classical steroid receptors. RU486 acted mainly on the more aggressive component of the SK-N-SH cell line and its effect in vivo was achieved at a concentration already used to inhibit oocyte implantation.

Expression and regulation of Enpp2 in rat uterus during the estrous cycle

Ectonucleotide pyrophosphatase/phosphodiestrase 2 (Enpp2) isolated from the supernatant of human melanoma cells is a lysophospholipase D that transforms lysophosphatidylcholine into lysophospatidic acid. Although multiple analyses have investigated the function of Enpp2 in the hypothalamus, its role in the uterus during the estrous cycle is not well understood. In the present study, rat uterine Enpp2 was analyzed by RT-PCR, Western blotting, and immunohistochemistry. Quantitative PCR analysis demonstrated that uterine Enpp2 mRNA was decreased during estrus compared to proestrus and diestrus. To determine whether uterine Enpp2 expression is affected by sex steroid hormones, immature rats were treated with 17beta-estradiol (E2), progesterone, or both on postnatal days 14 to 16. Interestingly, the expression of Enpp2 mRNA and protein were down-regulated by E2 in the uterus during estrus but not during proestrus or diestrus, suggesting that Enpp2 may play a role in uterine function during estrus. Enpp2 is primarily localized in the stromal cells of the endometrium during proestrus and estrus. During diestrus, Enpp2 was highly expressed in the epithelial cells of the endometrium. Taken together, these results suggest that uterine Enpp2 may be regulated by E2 and plays a role in reproductive functions during female rat development.

Effect of mifepristone on steroid receptor expression and biotransformation of oestrogen and progesterone in rat uterus and deciduoma.

BACKGROUND: [corrected] Mifepristone is a synthetic antiprogestin which terminates early pregnancy. Since it interferes with the progesterone maintained decidua, we compared the effect of mifepristone on oestrogen and progesterone receptors, and on the biotransformation of these hormones in normal and deciduous uterus. METHODS: Ovariectomized rats were treated with an oestrogen-progesterone hormone regimen and deciduoma was induced by trauma in one horn of the rat uterus while the other served as a control under an identical hormonal milieu. Hormone receptor and biotransformation studies were done using radiolabelled oestradiol and progesterone with high specific activity. RESULTS: The artificially formed decidual tissue was comparable with that of early pregnancy. Mifepristone replenished oestrogen and progesterone receptors which were suppressed by progesterone in both the normal and decidualized uterine horns. Inhibition of oestrogen receptors by progesterone correlated with decreased oestradiol levels at the site of action. Metabolism of progesterone to less potent compounds was promoted by mifepristone. The enzymatic activities of 17beta-hydroxysteroid dehydrogenase (which metabolizes oestradiol), and 20alpha-hydroxysteroid dehydrogenase and 5alpha-reductase (which metabolize progesterone) were altered by mifepristone. CONCLUSION: The effect of mifepristone in varying the hormone receptor population and the availability of different levels of active metabolites of ovarian hormones have an Important role in the antiprogestin action of mifepristone.

Electroacupuncture ameliorates experimental colitis induced by acetic acid in rat

The effect of electroacupuncture (EA) on experimental colitis was investigated in Sprague-Dawley rats. Colitis was induced by intracolonic instillation of 4% acetic acid. EA (2 Hz, 0.05 ms, 2 V for 20min) was applied to bilateral Hoku (LI-4) and Zusanli (ST-36) on 12 hrs and 36 hrs after induction of colitis. EA-treatment significantly reduced the macroscopic damage and the myeloperoxidase activity of colonic samples at 3 days post-induction of colitis. Colitic colon showed a decreased in vitro motility. However, colonic motility of EAtreated group was not significantly different from that of normal group. The anti-inflammatory effect of EA was not inhibited by a glucocorticoid receptor antagonist, RU-486, but suppressed by a beta-adrenoceptor antagonist, propranonol. These results suggest that EA-treatment has a beneficial effect on colitis, and its anti-inflammatory effect is mediated by beta-adrenoceptor activation but not by endogenous glucocorticoiddependent mechanism.

Contranidatory activity of early luteal phase administration of mifepristone in the rhesus monkey.

The contranidatory action of mifepristone (RU 486) given as a single application at different dosages to mated rhesus monkeys (Macaca mulatta) on second day after ovulation has been examined in the present study. In group 1, monkeys (n = 3) received only vehicle (benzyl benzoate: olive oil, 1:4, v/v) and were treated as controls. In group 2 monkeys (n = 4), RU 486 was given by gavage at 10 mg/kg in group 4 (n = 5). The patterns of cycles and profiles of serum estrogen and progesterone were monitored for assessing the occurrence of implantation and pregnancy. At a single dose of 10 mg/kg, RU 486 was found to be ineffective in preventing nidation, resulting pregnancy in three females out of four treated monkeys. Similarly, an s.c. administration of 1 mg/kg could provide pregnancy protection in two of the four treated monkeys. In these monkeys, however, the menstrual cycle characteristics were not affected as compared to pretreatment cycles. Interestingly, the administration of 2 mg/kg, s.c., RU 486 could provide a hundred percent pregnancy protection in mated monkeys, and there was no significant changes in the pattern of menstrual cycle characteristics. It appears that an early post-ovulatory administration of RU 486 may be successfully used in human as an effective once-a-month, early luteal phase contranidatory agent.