Cholecystokinin inhibits gastrin secretion independently of paracrine somatostatin secretion in the pig.
BACKGROUND
Cholecystokinin inhibits the secretion of gastrin from antral G cells, an effect that is speculated to be mediated by D cells secreting somatostatin. The aim of the study was to test directly whether cholecystokinin inhibition of antral gastrin secretion is mediated by somatostatin.


METHODS
The effects of CCK on gastrin and somatostatin secretion were studied in isolated vascularly perfused preparations of pig antrum before and after immunoneutralization brought about by infusion of large amounts of a high affinity monoclonal antibody against somatostatin.


RESULTS
CCK infusion at 10(-9) M and 10(-8) M decreased gastrin output to 70.5% +/- 7.6% (n = 8) and 76.3% +/- 3.6% (n = 7) of basal output, respectively. CCK at 10(-10) M had no effect (n = 6). Somatostatin secretion was dose-dependently increased by CCK infusion and increased to 268 +/- 38.2% (n = 7) of basal secretion during infusion of CCK at 10(-8) M. Immunoneutralization of somatostatin caused a doubling of the basal secretion of gastrin, but did not affect the CCK-induced decrease in gastrin secretion.


CONCLUSIONS
CCK inhibits gastrin secretion independently of paracrine somatostatin secretion.
Schmidt
P T
PT
Dept. of Medical Physiology, Panum Institute, Copenhagen, Denmark.
Hansen
L
L
Hilsted
L
L
Holst
J J
JJ
D000818:Animals; D002766:Cholecystokinin / Q000494:pharmacology / Q000502:physiology*; D019863:Gastrin-Secreting Cells / Q000502:physiology; D005755:Gastrins / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D019899:Paracrine Communication / Q000502:physiology*; D011706:Pyloric Antrum / Q000378:metabolism*; D011863:Radioimmunoassay; D013004:Somatostatin / Q000378:metabolism*; D019864:Somatostatin-Secreting Cells / Q000502:physiology; D013552:Swine
D005755:Gastrins; D013004:Somatostatin; D002766:Cholecystokinin