Fig. 8.

Effect of E₂ on mRNA levels of gallbladder mucin genes as well as the genes involved in lipid transport and metabolism, and gallbladder motility in OVX wild-type, GPR30(^−/−), ERα(^−/−), and GPR30(^−/−)/ERα(^−/−) mice treated with E₂ at 0 or 6 µg/day and fed the lithogenic diet for 12 days. The mRNA levels of these genes in OVX wild-type mice receiving no E₂ and fed the lithogenic diet for 12 days are set at 1. Treatment of E₂ at 6 µg/day significantly increases mRNA levels of Muc2, Muc5ac, Muc5b, Acat2, Abcg5, Abcg8, Abca1, and Sr-b1 in OVX wild-type, GPR30(^−/−), and ERα(^−/−), but not GPR30(^−/−)/ERα(^−/−) mice. However, expression of Cck-1r is significantly reduced in OVX wild-type and GPR30(^−/−) but not ERα(^−/−) or GPR30(^−/−)/ERα(^−/−) mice. Notably, expression of Muc1, Muc3, and Muc4 in the gallbladder is comparable in the five groups of mice. See text for further description and for abbreviations.