Fig. 7.

Effect of E₂ on the expression of the Erα, Erβ, and Gpr30 genes in the gallbladder. The data are expressed relative to mRNA levels of Erα, Erβ, and Gpr30 in the gallbladder of OVX wild-type mice treated with E₂ at 0 or 6 µg/day and fed the lithogenic diet for 12 days, and their relative expression levels are set at 1. Treatment of E₂ at 6 µg/day results in a significant increase in mRNA levels of the gallbladder Erα but not Erβ or Gpr30 genes in OVX wild-type and GPR30(^−/−) mice. Notably, expression of Erβ and Gpr30 is low in the gallbladder. The absence of Erα and Gpr30 expression in the gallbladder confirms their complete knockout in OVX ERα(^−/−), GPR30(^−/−), and GPR30(^−/−)/ERα(^−/−) mice, respectively. See text for details.