AJP - Gastrointestinal and Liver Physiology, Vol 238, Issue 6 531-G536, Copyright © 1980 by American Physiological Society
Prostacyclin inhibits pancreatic secretion
S. J. Konturek, J. Tasler, J. Jaworek, M. Cieszkowski and W. Pawlik
Prostacyclin (PGI2), the major product of arachidonate metabolism in the
gastrointestinal tract, was shown to affect gastric blood flow and gastric
secretion, but it is unknown whether it also affects pancreatic secretion.
This study was designed to determine the influence of PGI2 on pancreatic
secretion under basal conditions and in response to exogenous and
endogenous stimulants. PGI2 alone given in graded intravenous doses caused
a slight pancreatic bicarbonate and protein secretion in fasted dogs. When
given during stimulated pancreatic secretion, PGI2 caused a potent
inhibition of the bicarbonate and protein secretion induced by feeding a
liver meal, by duodenal perfusion with hydrochloric acid or amino acid
mixture, and by intravenous infusion of secretin or caerulein. The kinetic
analysis showed that the interaction between PGI2 and secretin affecting
bicarbonate secretion is of a mixed type (increased half-maximal dose
response, decreased calculated maximal response). This indicates that PGI2
decreases both the total secretory capacity of the pancreas to secrete
bicarbonate and reduces the sensitivity of the pancreatic secretory cells
to secretin. Because PGI2 significantly reduced the arterial blood
pressure, its inhibitory effects on pancreatic secretion could be due, at
least in part, to the interference of the blood flow to the pancreas.
