17β-Estradiol relaxes cholecystokinin- and KCl-induced tension in male guinea pig gallbladder strips

► 17β-Estradiol relaxes both cholecystokinin and KCl-induced tension. ► The PKA\cAMP, PKG, and PKC second messengers systems do not mediate the relaxation. ► Inhibition of extracellular Ca2+ entry mediates the 17β-estradiol-induced relaxation.