RTI uses cookies to offer you the best experience online. By clicking “accept” on this website, you opt in and you agree to the use of cookies. If you would like to know more about how RTI uses cookies and how to manage them please view our Privacy Policy here. You can “opt out” or change your mind by visiting: http://optout.aboutads.info/. Click “accept” to agree.
We evaluated the effect of commonly used pharmaceutical estrogens and zeranol, an estrogenic growth-promoting agent used in livestock, on progesterone (P) production by cultures of highly differentiated porcine granulosa cells (GC). The compounds were added to GC cultures over a dose range of 10(-8) to 10(-5) M with P and cell protein measured after 24 h. P production was suppressed by estradiol (minimal suppressive dose: 10(-7) M; maximal suppression to 11% of control), ethinyl estradiol (10(-7) M, 15%), diethylstilbestrol (10(-5) M, 72%), clomiphene citrate (10(-6) M, 30%), nafoxidine (10(-7) M, 33%), tamoxifen (10(-6) M, 37%), and zeranol (10(-5) M, 83%). P production was not suppressed by mestranol. GC protein was suppressed by estradiol, ethinyl estradiol, nafoxidine, and zeranol. These data suggest that synthetic estrogens have the potential to suppress luteal P production by a mechanism unrelated to the usual measures of estrogenicity
RTI shares its evidence-based research - through peer-reviewed publications and media - to ensure that it is accessible for others to build on, in line with our mission and scientific standards.