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.