Gastric and enteral pancreatic polypeptide (PP) immunoreactivity in the dog

Extrapancreatic pancreatic polypeptide (PP) was quantified by determination of PP-cell density using antibodies to human PP (hPP) and bovine PP (bPP) in stomach, duodenum, jejunum, ileum, and colon of the dog. Further, these organs of 3 beagles were extracted and subjected to radioimmunoassay again using 2 different antisera (one directed against bPP, the other against hPP). Purification of these extracts were performed by Sephadex chromatography. We found bPP immunoreactive cells in stomach, small and large bowel, but hPP immunoreactive cells, besides in the pancreas, only in stomach and duodenum, thus demonstrating heterogeneity of extrapancreatic PP. Extraction and chromatography confirm the presence of PP immunoreactivity in the pancreas, stomach, small and large intestine. The observation of a postprandial rise of serum PP levels in a man with total duodenopancreatectomy suggests that the extrapancreatic PP cell may release PP.