Cells were treated with vehicle (V), estradiol (E2), estrone (E1), estriol (E3), bisphenol A (BPA), ethylphenol (EP), propylphenol (PP), octylphenol (OP) and nonylphenol (NP) for 5 min, all estrogens at 1nM, except that BPA was additionally tested at 10 fM. GTP-bound Gαi (A) and Gαs (B) were measured by recognition with an Ab selective for these GTP-bound forms in the absence (white bar) or presence (dark bar) of 100μM GTPγS. Total Gαi and Gαs were also measured, but did not differ under any conditions of estrogen treatments (data not shown). For statistical annotations: For A *= statistical significance (P<0.05) from paired V control for the no GTPγS group. #= GTPγS-treated group statistical significance (P<0.05) from paired estrogen-treated levels; n=48 without, and n=32 with GTPγS treatment over 3 experiments. For B n=32 without and n=16 with GTPγS treatment over 2 experiments.