Nongenomic Actions of Estrogens and Xenoestrogens by Binding at a Plasma Membrane Receptor Unrelated to Estrogen Receptor α and Estrogen Receptor β

The molecular mechanism used by environmental chemicals to exert their hormone-like actions is still only partially resolved. Although it generally is accepted that xenoestrogens act at the genomic level by binding to intracellular estrogen receptors, we have shown here that they trigger nongenomic effects in pancreatic β cells. Both xenoestrogens and the circulating hormone, 17β -estradiol, bind with high affinity to a common membrane binding site unrelated to the intracellular estrogen receptors ERα and ERβ . This binding site is shared by dopamine, epinephrine, and norepinephrine and has the pharmacological profile of the γ -adrenergic receptor. This study provides an outline of the membrane receptor involved in rapid xenoestrogen actions.