Abstract
[Ψ4,5]Secretin was shown to be a secretin receptor antagonist that inhibits secretin-stimulated increase in adenosine 3',5'-cyclic monophosphate in isolated pancreatic acini of the guinea pig. To determine whether it inhibits pancreatic exocrine secretion in vivo, we have studied the effect of [Ψ4,5]secretin on the pancreatic secretion stimulated by secretin in anesthetized guinea pigs and rats. In basal state, [Ψ4,5]secretin given intravenously for 2 or 3 h in varying doses of 1.6-32.7 nmol · kg-1 · h- 1 dose dependently increased pancreatic secretion of both fluid and bicarbonate during the 1st h, but it returned gradually to basal level within 2 or 3 h. On the other hand, [Ψ4,5]secretin significantly inhibited the pancreatic secretion stimulated by either exogenous or endogenous secretin in a dose-related manner. The inhibitory effect of [Ψ4,5]secretin in guinea pigs was greater than that in rats. However, it did not completely block the secretin-stimulated pancreatic secretion, whereas a rabbit antisecretin serum suppressed it completely. We conclude that 1) in the unstimulated state, [Ψ4,5]secretin is a partial agonist of pancreatic exocrine secretion of both fluid and bicarbonate; and 2) when pancreatic secretion is stimulated by secretin, unlike an antisecretin serum, it is a partial inhibitor in intact guinea pigs and rats.
Original language | English |
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Pages (from-to) | G805-G810 |
Journal | American Journal of Physiology - Gastrointestinal and Liver Physiology |
Volume | 265 |
Issue number | 5 28-5 |
DOIs | |
Publication status | Published - 1993 |
Externally published | Yes |
Keywords
- carbachol
- cholecystokinin octapeptide
- secretin antagonist
ASJC Scopus subject areas
- Physiology
- Hepatology
- Gastroenterology
- Physiology (medical)