Direct contractile response of isolated gallbladder smooth muscle cells to cholecystokinin in patients with gallstones.

To examine whether the contractile response of gallbladder smooth muscle cells to cholecystokinin is reduced in patients with gallstones, smooth muscle cells were isolated from the gallbladders of patients either with or without gallstones and their direct contractile responses to cholecystokinin-octapeptide (CCK-8) were examined at physiological concentrations. The basal cell lengths were similar in patients with cholesterol gallstones (43 +/- 1.2 micron (SEM)), in patients with black pigment stones (42 +/- 1.1), and in the gallstone-free group (42 +/- 1.3). The contractile responses to CCK-8 at physiological concentrations ranging from 10(-13) to 10(-11) M were significantly greater in the gallstone patients compared with those in the gallstone-free patients, while the responses were similar at 10(-10) and 10(-9) M. No difference in contractile response to CCK-8 was found between the patients with cholesterol gallstones and those with black pigment stones. The effective dose of 50% was 1.6 x 10(-13) M in cholesterol gallstone patients, 3.2 x 10(-14) M in black pigment stone patients, and 1.0 x 10(-12) M in gallstone-free patients. The current in vitro study showed that the contractile responses of isolated smooth muscle cells of the gallbladder to CCK-8 are not impaired in patients with gallstones.