Prevention of implantation by antiprogesterone
| Autor: | Béla A. Resch, Arpad I. Csapo |
|---|---|
| Rok vydání: | 1979 |
| Předmět: |
medicine.medical_specialty
Time Factors Side effect medicine.medical_treatment Uterus Embryonic Development Normal pregnancy Endometrium Biochemistry Steroid Single oral dose Endocrinology Pregnancy Internal medicine medicine Animals Embryo Implantation Progesterone Chemistry Fetal Resorption Isoxazoles medicine.disease Rats Androstadienes medicine.anatomical_structure Pregnenolone Female medicine.drug |
| Zdroj: | Journal of Steroid Biochemistry. 11:963-969 |
| ISSN: | 0022-4731 |
| DOI: | 10.1016/0022-4731(79)90039-6 |
| Popis: | If progesterone (P) is indispensable in the protection of normal pregnancy during the pre-implantation period, then treatment with antiP (AP), should prevent implantation. The validity of this premise has been examined in the rat model, using the synthetic steroid: Isoxazol. This AP inhibits the conversion of pregnenolone to P, by inhibiting the enzyme 3β-HSDH. In an earlier study, a single oral dose of 2.5 mg Isoxazol invariably interrupted pregnancy shortly after implantation and 20 mg predictably provoked parturition preterm. In the present study, conducted between days 0 and 4 of the pre-implantation period, a single oral dose of 20 to 100 mg Isoxazol has been administered to spermpositive rats. The controls were treated with vehicle only. At day 4, when the blastocysts are already loosely attached to the endometrium, 40 mg Isoxazol compromised normal implantation, as a rule, and the conceptuses became resorbed. At day 3, when the morulas enter the uterus, this dose had a moderate effect only while 60 mg increased efficacy and 100 mg prevented the implantation of most blastocysts. As in the previous studies a single dose of AP provoked a drastic P withdrawal (Pw). The premise that it was Pw and not some side effect of Isoxazol which intercepted normal implantation was verified by the demonstration that the prevention of the AP-induced Pw, by P treatment, prevented the antifertility action of Isoxazol. |
| Databáze: | OpenAIRE |
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