Further investigations of intestinal hormonal polypeptides

Attempts are described to identify additional polypeptides of hormonal nature in a concentrate of intestinal polypeptides shown previously to contain secretin, cholecystokinin-pancreozymin (CCK), motilin, gastric inhibitory polypeptide (GIP), vasoactive intestinal polypeptide (VIP), enteroglucagon and chymodenin. The probable amino acid sequence of a variant form of CCK is disclosed. The possibility of using characteristic fragments of polypeptides for the quantitation of the polypeptides themselves in crude preparations is briefly discussed.