Somatostatin inhibits cholecystokinin-induced contraction of isolated gallbladder smooth muscle cells.

A close relation between the hyperhormonism of somatostatin and gallstone disease suggested to us the hypothesis that somatostatin inhibits cholecystokinin (CCK)-induced gallbladder contraction on the level of target organs. To investigate this hypothesis, smooth muscle cells were isolated from human and canine gallbladders and the direct inhibitory effects of somatostatin on the CCK-induced cell contraction were examined in vitro. Somatostatin alone had no effect on the cell motility, while it significantly inhibited the cholecystokinin-octapeptide (10(-10) M)-induced cell contraction at the concentration of 10(-6) M (P < 0.01) in both human and canine gallbladders. The results demonstrate for the first time that somatostatin has a direct inhibitory action against cholecystokinin-induced gallbladder contraction. This may partly account for the high frequency of gallstone disease in patients with somatostatinoma.