Effect of paternal administration of an antiestrogen, tamoxifen on embryo development in rats

Reproductive toxicity assessment of lasofoxifene, a selective estrogen receptor modulator (SERM), in male rats

“…Treatment with raloxifene or idoxifene had no effect on the number of viable embryos (Hoyt et al, 1998;Treinen et al, 1998); however, tamoxifen and the anti-estrogen ICI 182,780 reduced the number of copulating males producing pregnancy and the number of implantation sites per copulation (Gill-Sharma et al, 1993;Parte et al, 2000;Oliveira et al, 2001;Balasinor et al, 2001). Balasinor et al (2001Balasinor et al ( , 2002 have suggested that tamoxifen causes a reduction in the number of implantation sites per copulation by decreasing survival of pre-implantation embryos, not by reducing the number of fertilized ova (Gill-Sharma et al, 1993). The effect of tamoxifen on the number of implantation sites was lessened by coadministration of DHT, suggesting that androgen is an important factor for fertilizing ability of sperm (Parte et al, 2000).…”

Effect of tamoxifen treatment on the semen quality and fertility of the male rat

“…In other studies, it was also pointed out that long-term oral tamoxifen treatment caused reduction in viable litters sired by treated male rats after 60 days of exposure (30). These studies suggested that paternal factors sensitive to tamoxifen are involved in embryogenesis.…”

Aberrant methylation of multiple imprinted genes in embryos of tamoxifen-treated male rats

“…Studies from our laboratory have shown that tamoxifen treatment of adult male rats at a dose of 0.4 mg/kg per day (equivalent to human tamoxifen therapy) for 60 days results in an increase in pre-and postimplantation loss (POL) but the rate of fertilization is unaltered (Balasinor et al 2001). Histology of the resorptions (at E20) showed the presence of trophoblast outgrowths, which are suggestive of early placentation, leading us to conclude that the POL might have commenced around E9-E11 (Balasinor et al 2002). Embryos at E13 have just started resorbing and are not dead; hence, we refer to them as 'resorbing embryos' hereafter.…”