In vivo and in vitro antiestrogenic action of 3-hydroxytamoxifen, tamoxifen and 4-hydroxytamoxifen

The Estrogenic and Antiestrogenic Activities of Droloxifene in Human Breast Cancers

“…The results in this study are consistent with our previous findings using the index of rat uterine weight. Loser et al also reported the same findings on DROL in uterotropic and anti uterotropic tests in rats (13). On the other hand, the growth of ER-negative human breast cancer cells, MDA MB-231, was not influenced by E2, DROL or TAM.…”

The Estrogenic and Antiestrogenic Activities of Droloxifene in Human Breast Cancers

“…The results in this study are consistent with our previous findings using the index of rat uterine weight. Loser et al also reported the same findings on DROL in uterotropic and anti uterotropic tests in rats (13). On the other hand, the growth of ER-negative human breast cancer cells, MDA MB-231, was not influenced by E2, DROL or TAM.…”

No loss of estrogenic or anti‐estrogenic activity after demethylation of droloxifene (3‐OH‐Tamoxifen)

“…The results represent the mean of 10 animals k SD/test group. earlier (Loser and Hofrichter, 1982;Loser et al, 1985;Eppenberger et al, 1984). TAM had a much lower affinity for the cytoplasmic ER than DROL or ND-DROL, as shown in Figure 1.…”

“…TAM had a much lower affinity for the cytoplasmic ER than DROL or ND-DROL, as shown in Figure 1. The estrogenic activity of 3 and 9 mg/kg DROL and ND-DROL was measured in immature female rats in terms of increase in uterine weight (uterotropic effect) (Loser et al, 1985). Figure 2 indicates that uterine growth is equally dose-dependent on DROL and ND-DROL.…”

Comparison of the DNA adducts formed by tamoxifen and 4-hydroxytamoxifen in vivo

“…(Z)-4-hydroxytamoxifen (42,43)]. The observed decrease in uterine weight with tamoxifen and 4-hydroxytamoxifen is consistent with their antiestrogenic activities (44,45). 4-Hydroxytamoxifen is a relatively minor metabolite of tamoxifen, with the major metabolic pathway being N-demethylation to N-desmethyltamoxifen (46,47).…”

The Estrogenic and Antiestrogenic Activities of Droloxifene in Human Breast Cancers

“…The results in this study are consistent with our previous findings using the index of rat uterine weight. Loser et al also reported the same findings on DROL in uterotropic and anti uterotropic tests in rats (13). On the other hand, the growth of ER-negative human breast cancer cells, MDA MB-231, was not influenced by E2, DROL or TAM.…”

No loss of estrogenic or anti‐estrogenic activity after demethylation of droloxifene (3‐OH‐Tamoxifen)

“…The results represent the mean of 10 animals k SD/test group. earlier (Loser and Hofrichter, 1982;Loser et al, 1985;Eppenberger et al, 1984). TAM had a much lower affinity for the cytoplasmic ER than DROL or ND-DROL, as shown in Figure 1.…”

“…TAM had a much lower affinity for the cytoplasmic ER than DROL or ND-DROL, as shown in Figure 1. The estrogenic activity of 3 and 9 mg/kg DROL and ND-DROL was measured in immature female rats in terms of increase in uterine weight (uterotropic effect) (Loser et al, 1985). Figure 2 indicates that uterine growth is equally dose-dependent on DROL and ND-DROL.…”

Comparison of the DNA adducts formed by tamoxifen and 4-hydroxytamoxifen in vivo

“…(Z)-4-hydroxytamoxifen (42,43)]. The observed decrease in uterine weight with tamoxifen and 4-hydroxytamoxifen is consistent with their antiestrogenic activities (44,45). 4-Hydroxytamoxifen is a relatively minor metabolite of tamoxifen, with the major metabolic pathway being N-demethylation to N-desmethyltamoxifen (46,47).…”

The Estrogenic and Antiestrogenic Activities of Droloxifene in Human Breast Cancers

“…The results in this study are consistent with our previous findings using the index of rat uterine weight. Loser et al also reported the same findings on DROL in uterotropic and anti uterotropic tests in rats (13). On the other hand, the growth of ER-negative human breast cancer cells, MDA MB-231, was not influenced by E2, DROL or TAM.…”

No loss of estrogenic or anti‐estrogenic activity after demethylation of droloxifene (3‐OH‐Tamoxifen)

“…The results represent the mean of 10 animals k SD/test group. earlier (Loser and Hofrichter, 1982;Loser et al, 1985;Eppenberger et al, 1984). TAM had a much lower affinity for the cytoplasmic ER than DROL or ND-DROL, as shown in Figure 1.…”

“…TAM had a much lower affinity for the cytoplasmic ER than DROL or ND-DROL, as shown in Figure 1. The estrogenic activity of 3 and 9 mg/kg DROL and ND-DROL was measured in immature female rats in terms of increase in uterine weight (uterotropic effect) (Loser et al, 1985). Figure 2 indicates that uterine growth is equally dose-dependent on DROL and ND-DROL.…”

Comparison of the DNA adducts formed by tamoxifen and 4-hydroxytamoxifen in vivo

“…(Z)-4-hydroxytamoxifen (42,43)]. The observed decrease in uterine weight with tamoxifen and 4-hydroxytamoxifen is consistent with their antiestrogenic activities (44,45). 4-Hydroxytamoxifen is a relatively minor metabolite of tamoxifen, with the major metabolic pathway being N-demethylation to N-desmethyltamoxifen (46,47).…”