Toxicological Study on RU 486

Deraedt, R.; Vannier, Bernard; Fournex, R.

doi:10.1007/978-1-4684-1242-0_10

Cited by 17 publications

(9 citation statements)

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“…Below this dose it did not produce any significant effect on the incidence of resorbing implants. Also it had no effect on the fetal weight of surviving fetuses which is in agreement with the previous observation of Deraedt et al 27 . This outcome is also consistent with the recently reported observations from using RU486 in clinical practice to induce abortion.…”

Section: Discussionsupporting

confidence: 93%

The effects of the antihormones RU486 and tamoxifen on fetoplacental development and placental bed vascularisation in the rat: a model for intrauterine fetal growth retardation

Bell

1996

BJOG

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Objective To examine the effect of administration of the antihormones RU486 and tamoxifen in early pregnancy during the period of maximal decidual development in the rat upon fetoplacental and placental bed development.Design Case-control study in an experimental animal model.Setting Academic department of obstetrics and gynaecology in a UK medical school. Animals Small laboratory animal-the rat-exhibiting haemochorial placentation.Intervention Administration of antiprogesterone or antioestrogen (RU486 and tamoxifen respectively) during early pregnancy. Main outcome measuresWeight of the whole pregnancy implant, fetus, mesometrial decidua and placenta ; incidence of intrauterine fetal death ; and histological changes in the placental bed.Results RU486 produced resorption of all implants when administered above a threshold dose, below which it had no effect upon subsequent fetoplacental development. Tamoxifen treatment on days 9 to 11 resulted in significant reduction of decidual weight (35.1 O h on day 12 of pregnancy, P < 0.001). This was associated with a higher rate of implants or fetuses weighing below the 10th centile (59.6 YO and 5.7 % on day 12, P < 0.001 ; 42.9 % and 7 % on day 16, P < 0.001 ; 25-4 YO and 7.6 YO on day 20, P < 0.001 in treated and control animals, respectively). This was also associated with a higher rate of intrauterine fetal death (30.7% on day 16 compared with 4.5 % in controls, P < 0001 ; 47.8 % on day 20 compared to 0.83 Yo in controls, P < 0.001). Histologically, the placental bed of treated animals failed to develop a dilated uteroplacental artery although trophoblast cells migrated endovascularly to a level equivalent to untreated animals.Conclusions RU486 had an all or none dose-dependent effect on fetoplacental development, resulting in either abortion or normal development of pregnancy. Tamoxifen produced significant impairment of decidual development, which was associated with altered blood vessel transformation in the placental bed, impaired fetoplacental development and higher incidence of growth retarded fetuses and fetal death.

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Section: Discussionsupporting

confidence: 93%

The effects of the antihormones RU486 and tamoxifen on fetoplacental development and placental bed vascularisation in the rat: a model for intrauterine fetal growth retardation

Bell

1996

BJOG

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“…By placing a tissue-specific promoter with the regulator, it should be possible to regulate both tissue-specific and inducible expression ofa given target gene to study its function in vivo in transgenic animals. In addition, developmental studies in transgenic animals would be feasible because RU 486 has been shown not to be an abortifacient in rats at doses <0.5 pg/kg (32). Perhaps most importantly, its inducible characteristics can be used to generate disease models (or induce therapeutic proteins) in transgenic animals at adult periods of their life cycles.…”

Section: Resultsmentioning

confidence: 99%

A regulatory system for use in gene transfer.

Wang

Tsai

O’Malley

1994

Proc. Natl. Acad. Sci. U.S.A.

419

293

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“…To raise the efficiency of recombination more rapidly, the following strategies may be considered; changing the protocol of RU486 administration, replacing the solvent of the steroid and trying other types of antiprogesterone such as Org31806. The effects of RU486 in the nervous system remain to be examined, but RU486 has been reported to be a non-toxic after acute (1 g/kg) and chronic administration (200 mg/kg/day for 30 days) (21).…”

Section: Discussionmentioning

confidence: 99%