Tamoxifen, 4-hydroxytamoxifen and desmethyltamoxifen levels were measured in cytosolic and 0.5 M KCl extracted nuclear fractions from a small series of breast tumours from tamoxifen treated patients by gas chromatography-mass spectrometry (GC-MS) using selected ion monitoring (SIM). Tamoxifen and desmethyltamoxifen were the most abundant metabolites. There was a small increment in the relative abundance of 4-hydroxytamoxifen in the nuclear extract over cytosol relative to both tamoxifen and desmethyltamoxifen. Further, there was a selective retention of tamoxifen relative to desmethyltamoxifen in the nuclear extract relative to the cytosol. It is concluded that all three compounds could potentially contribute to estrogen receptor mediated antiestrogenic effects in this target tissue.
Bibliographical noteM1 - 6
Murphy, C Fotsis, T Pantzar, P Adlercreutz, H Martin, F Research Support, Non-U.S. Gov't England Journal of steroid biochemistry J Steroid Biochem. 1987 Dec;28(6):609-18.
- Breast Neoplasms/*analysis Cell Nucleus/analysis Cytosol/analysis Female Gas Chromatography-Mass Spectrometry Humans Potassium Chloride/pharmacology Tamoxifen/*analogs & derivatives/*analysis