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The concomitant in vivo exposure of young male adult rats to the pesticide methoxychlor (M) and the antiestrogen ICI 182,780 (ICI) does not alter the declines in seminal vesicle (SV) weight, serum testosterone (T) level, ex vivo leydig cell (LC) T formation, or ex vivo LC P450 cholesterol...

Murono-EP; Derk-RC; Akgul-Y
Toxicologist 2006 Mar; 90(1):431
M is a pesticide used as a replacement DDT. It exhibits weak estrogenic and/or antiandrogenic activities, and its adverse reproductive effects are thought to be mediated through either the estrogen receptor (ER) or androgen receptor(AR). The current studies evaluated whether the declines in SV weight, serum T level, and ex vivo LC T formation and P450scc activity exerted by the in vivo exposure of young adult male rats to M alone are prevented by the concomitant treatment with ICI. Animals received a single injection (s.c.) of arachis oil alone or ICI (10 mg/kg b.wt.) dissolved in arachis oil 3 days prior to M exposure. At 54 days of age, animals were gavaged with corn oil alone or M dissolved in corn oil (200 mg/kg b.wt., once daily for 7 consecutive days). Animals were sacrificed 22-24 h after the last exposure. There were 12-13 animals per treatment group. Treatment with M alone decreased SV weight, serum T level, ex vivo basal LC T formation, and ex vivo LC P450scc activity to 42, 46, 39, and 53% of control, respectively. Concomitant treatment with ICI had no effect on these declines produced by M alone. In addition, animals exposed to ICI alone had values no different than control animals. These results suggest that the inhibitive effects of M on some male reproductive functions are not mediated through the ER.
Pesticides; Pesticides-and-agricultural-chemicals; Agricultural-chemicals; Laboratory-animals; Animals; Animal-studies; Exposure-levels; Exposure-assessment
Publication Date
Document Type
Fiscal Year
Issue of Publication
NIOSH Division
Priority Area
Disease and Injury: Fertility and Pregnancy Abnormalities
Source Name
The Toxicologist. Society of Toxicology 45th Annual Meeting and ToxExpo, March 5-9, 2006, San Diego, California
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division