The distribution of polypeptide YY (PYY) - and pancreatic polypeptide (PP) - immunoreactive cells in the domestic fowl.

The distribution of the polypeptide which has an N-terminal tyrosine and a C-terminal tyrosine (PYY) - and pancreatic polypeptide (PP) - immunoreactive cells were investigated in the gut of the domestic fowl. PPY-immunoreactive cells were observed in the duodenum and jejunum. PP-immunoreactive cells were seen in the duodenum, jejunum, ileum and colon. Both PYY- and PP-immunoreactive cells were extended from the basal lamina to the gut lumen i.e. of open type. PYY-immunoreactive cells occurred mainly in the basal and middle portion of the villi. On the other hand, PP-immunoreactive cells were located mostly in the crepts. The occurrence of PYY-immunoreactive cells in the upper part of the small intestine is rather similar to that of amphibians and reptiles, than to that of mammals, where PYY-immunoreactive cells are located in the distal part of the small intestine and in the large intestine.