The Hormonal and Antifertility Activity of 2,6-cis-Diphenylhexamethylcyclotetrasiloxane in the Female Rat* |
| |
| Authors: | R. R. Le Vier M. E. Jankowiak |
| |
| Abstract: | Abstract: An organosilicon compound, 2,6-cis-diphenylhexamethylcyclotetrasiloxane, cyclic 2,6-[(PhMeSiO)2(Me2SiO)2], was shown to be an orally active estrogen in the mature castrate rat; about 1.0 mg/kg is equivalent to 0.005 mg/kg estradiol benzoate used as a maximum stimulatory dose in a uterotropic assay. Cyclic 2,6-cis-[(PhMeSiO)2 (Me2SiO)2] is not an antiestrogen. Cyclic 2,6-cis-[(PhMeSiO)2 (Me2SiO)2] is an effective oral postcoital antifertility agent when administered at 0.33 mg/kg on days 1–5 of gestation and at 3.0 mg/kg given on day 1 of gestation. The primary effect appeared to be accelerated passage of ova to the uterus and induction of ovum destruction in the oviduct. At the doses used cyclic 2,6-cis-[(PhMeSiO)2 (Me2SiO)2] was similar to diethylstilbestrol in that tubal retention did not occur as shown for estradiol benzoate. Administration of cyclic 2,6-cis-[(PhMeSiO)2 (Me2SiO)2] at other times during gestation terminated pregnancy during primitive streak and neurula stages (days 8–11). Gestation was less sensitive to organosiloxane treatment during implantation. Pregnancy was not terminated after day 11. Thus, this purely organosilicon compound represents a new class of moderate estrogens and may be useful in the study of estrogen structure-activity relationships. |
| |
| Keywords: | |
|
|
