Sex steroid hormone receptors and human gallbladder motility in vitro

This study was designed to investigate the relationship between estrogen and progesterone receptor levels and in vitro contractile response of gallbladder muscle strips to stimulation by carbachol and cholecystokinin-octapeptide (CCK-OP). Seventeen female postmenopausal patients cholecystectomized for gallstones were studied. Samples of the gallbladder wall were used for histological examination; motility was studied by Keane et al. [Surg Gynecol Obstet 1986; 163:555-560]; the estrogen and progesterone receptor levels were evaluated by immunoenzymatic assay. Positive correlations were found between the progesterone receptor level and the carbachol concentration that produced half the maximal response (ED50), and between the estrogen receptor level and the ED50 of CCK-OP. Our data confirm the presence of estrogen and progesterone receptors in the gallbladder and suggest that sex steroid hormones act on gallbladder motility by modulating the affinity of gallbladder receptors to CCK-OP and carbachol.