Past Oral Contraceptive Use and Current Dietary Soy Isoflavones Influence Estrogen Metabolism in Postmenopausal Monkeys (Macaca Fascicularis)
Cancer Epidemiology, Biomarkers & Prevention
PubMed Central® ID
Estrogen metabolism may play an important role in mammary carcinogenesis in postmenopausal women. We evaluated the effects of prior oral contraceptive (OC) treatment and current soy isoflavone consumption on endogenous estrogen metabolite concentration and biomarkers of tissue estrogen exposure in a monkey model. One hundred eighty-one female cynomolgus macaques were randomized to receive OC or placebo for 26 months premenopausally, then ovariectomized and randomized to one of three diets for 36 months: an isoflavone-depleted soy protein isolate (Soy-) diet, a diet containing soy protein isolate with a human equivalent of 129 mg isoflavone/d (Soy+), or a Soy- diet supplemented with conjugated equine estrogens (CEE+) at a human equivalent dose of 0.625 mg/d. Reverse-phase high-performance liquid chromatography directly coupled with tandem mass spectrometry was used to measure the concentrations of estrogen species in urine samples. Generally, prior OC treatment was associated with significantly reduced urinary estrogen metabolites (25-55% reduction; P
Biomarkers, chromatography, high pressure liquid, contraceptives, Oral, endometrium, estrogens, isoflavones, macaca fascicularis, mammary glands, postmenopause, soybean, proteins, spectrometry, mass, electrospray ionization
Scott, Latanya M.; Xu, Xia; Veenstra, Timothy D.; Tooze, Janet A.; Wood, Charles E.; Register, Thomas C.; Kock, Nancy D.; and Cline, J. Mark, "Past Oral Contraceptive Use and Current Dietary Soy Isoflavones Influence Estrogen Metabolism in Postmenopausal Monkeys (Macaca Fascicularis)" (2008). Pharmaceutical Sciences Faculty Publications. 321.