Nongenomic actions of estrogens and xenoestrogens by binding at a plasma membrane receptor unrelated to estrogen receptor alpha and estrogen receptorbeta

The molecular mechanism used by environmental chemicals to exert their horm one-like actions is still only partially resolved. Although it generally is accepted that xenoestrogens act at the genomic level by binding to intrace llular estrogen receptors, we have shown here that they trigger nongenomic effects in pancreatic beta cells. Both xenoestrogens and the circulating ho rmone, 17 beta-estradiol. bind with high affinity to a common membrane bind ing site unrelated to the intracellular estrogen receptors ER alpha and ER beta, This binding site is shared by dopamine, epinephrine. and norepinephr ine and has the pharmacological profile of the gamma-adrenergic receptor. T his study provides an outline of the membrane receptor involved in rapid xe noestrogen actions.