A comparison of the effects of various sex steroids on cholecystokinin- and KCl-induced tension in female guinea pig gallbladder strips

► Cholecystokinin and KCl induce tension in female guinea pig gallbladder strips. ► The strips are relaxed by progesterone, dihydrotestosterone, and 17β-estradiol. ► Gallbladder strips from young or pregnant female guinea pigs were relaxed by E2. ► E2 relaxation is not mediated by the PKA/cAMP, or PKG, or PKC, or NO. ► E2 relaxation is mediated by inhibiting extracellular Ca2+ entry.