Inhibitory regulation of rat exocrine pancreas by peptide YY and pancreatic polypeptide.
Peptide YY (PYY) and pancreatic polypeptide (PP) have been shown to inhibit exocrine pancreatic secretion in vivo in a variety of species. This study evaluates the type of stimulation inhibited by PYY and PP by examining, in urethan-anesthetized rats, the inhibition of pancreatic secretion when stimulated to a comparable extent by cholecystokinin (CCK), 2-deoxy-D-glucose (2DG), bethanecol, and electrical vagal nerve stimulation. PYY at maximal infusion rates inhibited stimulation by CCK by 83%, bethanecol by 55%, and electrical nerve stimulation by 40%. The inhibition of CCK stimulation was half maximal at 250 pmol.kg-1.h-1. By contrast, PYY totally inhibited 2DG-stimulated secretion with half-maximal inhibition at 10 pmol. kg-1.h-1. PP acted similarly to PYY in inhibiting CCK and 2DG-stimulated pancreatic protein secretion but was fivefold weaker in each case. These findings indicate that PYY and PP have multiple actions but preferentially inhibit neurally mediated pancreatic secretion at a preacinar cell locus, possibly at a central site of action.
Putnam
W S
WS
Cell Biology Laboratory, Mount Zion Hospital, University of California, San Francisco 94120.
Liddle
R A
RA
Williams
J A
JA
D000818:Animals; D018723:Bethanechol; D001626:Bethanechol Compounds / Q000494:pharmacology; D002766:Cholecystokinin / Q000494:pharmacology; D003847:Deoxyglucose / Q000494:pharmacology; D004558:Electric Stimulation; D008297:Male; D010179:Pancreas / Q000187:drug effects / Q000294:innervation / Q000378:metabolism*; D010191:Pancreatic Polypeptide / Q000494:pharmacology*; D019894:Peptide YY; D010455:Peptides / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014630:Vagus Nerve / Q000502:physiology
D001626:Bethanechol Compounds; D010455:Peptides; D011506:Proteins; D018723:Bethanechol; D019894:Peptide YY; D010191:Pancreatic Polypeptide; D002766:Cholecystokinin; D003847:Deoxyglucose