DEVELOPMENT AND REGULATION OF PORCINE PANCREATIC FUNCTION

A surgical and experimental procedure was developed to enable the coll ection of pure and inactivated pancreatic juice during the growth of t he pig. Studies have shown that, during the suckling period, both the basal and the secretory responses to suckling are low, if present at a ll. After weaning, basal levels of the total exocrine secretion, total protein, amylase, and trypsin, respectively, increase slightly, while the postprandial levels of total protein, amylase, trypsin, lipase, c olipase, and carboxylester lipase, respectively, increase markedly. Th e pancreatic juice enzyme composition changes qualitatively and the an tibacterial activity of the pancreatic juice also significantly increa ses. Piglet age appeared to be of minor importance, since weaning at e ither 4 or 6 wk of age gave the same results. Secretin and CCK adminis tered together in supraphysiological doses only significantly affect e xocrine function from 3-4 wk of age. However, CCK may also affect the exocrine pancreas indirectly via reflexes initiated intraduodenally. M ilk consumption in the suckling pig leads to a postprandial increase i n glucose levels but not insulin. Milk appears to be able to regulate the exocrine pancreas to produce only the amount and type of enzymes r equired for digestion. Thus, milk components or digestive products may affect pancreas function regulation. Studies show that enterostatin, the procolipase activation peptide, may inhibit pancreatic secretion m ediated indirectly through the GI tract. Pancreastatin, an endocrine p eptide, inhibits both insulin secretion and protein and trypsin secret ion to pancreatic juice. In hypoinsulinemic (alloxan + streptozotocin diabetes) pigs (15-20 kg), no postprandial pancreatic juice response i s seen, although CCK 33 + secretin can stimulate pancreatic secretion. Hypoinsulinemic pigs have a reduced capacity for glucose tissue utili zation, suggesting that tissue metabolism and exocrine pancreas secret ion are related.