Effects of cholecystokinin octapeptide on the pancreatic exocrine secretion in the pig.
In conscious pigs, intravenous infusion of serial doses of cholecystokinin octapeptide (CCK8; 2.9-232.3 pmol.kg-1.min-1) upon a background of secretin resulted in a linear increase of plasma CCK-like immunoreactivity (CCK-LI) concentration and evoked a dose-related increase of pancreatic volume and bicarbonate and protein outputs. The threshold plasma CCK-LI concentration for significant pancreatic response was 103.8 +/- 10.2 pM using a CCK8 dose of 8.8 pmol.kg-1.min-1. The maximum pancreatic response was observed for a plasma CCK-LI level of 498.0 +/- 15.3 pM using 77.2 pmol CCK8.kg-1.min-1. In anesthetized pigs, the threshold plasma CCK-LI concentration for pancreatic response was 1500 pM (actual CCK8 dose of 60.3 pmol.kg-1.min-1). The physiological relevance of this finding was assessed by comparing the food-induced increase of pancreatic secretion with that of plasma CCK-LI. Food ingestion was followed by a sharp pancreatic response and by a progressive increase of plasma CCK-LI to a peak increment of about 15 pM. Gel chromatography of portal and peripheral plasma from fed animals revealed three major peaks in the volumes of CCK33/39 and CCK8, and in a volume intermediate between CCK33/39 and CCK8. An additional minor component eluted ahead of CCK33/39. CCK8, which is one of the CCK components released after food intake, appears to be a fairly weak pancreatic stimulant in pigs.
Cuber
J C
JC
Centre de recherches de Jouy, Institut national de la recherche agronomique, Jouy-en-Josas, France.
Corring
T
T
Levenez
F
F
Bernard
C
C
Chayvialle
J A
JA
D000818:Animals; D001639:Bicarbonates / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D002850:Chromatography, Gel; D004435:Eating; D005755:Gastrins / Q000097:blood; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D011863:Radioimmunoassay; D012844:Sincalide / Q000097:blood / Q000276:immunology / Q000494:pharmacology*; D013552:Swine
D001639:Bicarbonates; D005755:Gastrins; D011506:Proteins; D012844:Sincalide