ON THE SIGNIFICANCE OF THE C-TERMINAL PRIMARY AMIDE IN CHOLECYSTOKININ

We report on the synthesis of some analogs of the C-terminal heptapept ide of cholecystokinin in which the C-terminal primary amide has been deleted and the L-tryptophan replaced by a D-tryptophan. These analogs were evaluated in vitro for their ability (i) to recognize the CCK re ceptor on rat pancreatic acini and on guinea pig brain membranes; (ii) to stimulate amylase release from rat pancreatic acini. Although prev ious works suggested that the C-terminal primary amide is essential fo r exhibiting a full biological response on pancreatic acini, this stud y does not confirm this hypothesis.