Action of fatty acids on the exocrine pancreatic secretion of the conscious rat: further evidence for a protein pancreatic inhibitory factor.

Abstract

SUMMARYThe existence of a delayed inhibition of the secretion of protein by the rat pancreas after intraduodenal injection of oleic acid has been confirmed.1. This phenomenon is not dependent on the presence or absence of bile or pancreatic juice in the intestine.2. The action of oleic acid is not a pathological-phenomenon due to lesions of the gut mucosa because isotonic solutions of Na oleate dispersed into polysorbate 80 or olive oil (rich in oleic acid) plus pancreatic juice have the same effect.3. Fatty acids must be free or saponified but not esterified in the form of triglycerides. Triglycerides are only effective if pancreatic juice is simultaneously reintroduced into the duodenum.4. Oleic acid (C18 monoene) is more efficient than caprylic acid (C8) and butyric acid (04) is ineffective. The effect of chain length in releasing the inhibitory factor is therefore approximately the same as in CCK-PZ release.5. Intraduodenal infusion of hypertonic glucose solution does not inhibit pancreatic protein secretion indicating that release of enteroglucagon is probably not responsible for the inhibition. The inhibitory action of hypertonic NaCl solution is not explained.

Is Na-butyrate a growth factor in the preruminant calf? Preliminary results

“…Intravenous injection (in anaesthetized pigs and calves or in conscious guinea pigs) and intra-duodenal perfusion (in rats) of Na-butyrate stimulated pancreatic secretion (Demol and Sarles, 1978;Harada and Kato, 1983;Kato et al, 1989;Katoh and Yajima, 1989). Feeding a diet enriched in butyrate, resulted in increased enzyme activities in the small intestinal mucosa (Galfi et al, 1993).…”

Mechanisms of Pancreatic Hypersecretion following Intraduodenal Hyperosmolar Glucose Infusion in Rats

“…In conscious rats, ID hyperosmolar NaCl decreased EPS, in accordance with several published papers [5, 6. 19], while other workers in similar con ditions found no change [4], Thus, hyperosmolarity per se may play a role but cannot explain all of the observed effects.…”

“…The intraduodenal (ID) infusion of hyperosmolar glucose solutions has been reported by different authors to give different effects, including a decrease [5,6], an increase [4,7] or no effect on EPS [8], We report that hyperosmolar glucose adminis tered intraduodenally in anesthetized rats, a model with low basal pancreatic secretion, stimulates the volume of pancreatic fluid and bicarbonate output in a dose-related manner.…”

“…ID glucose infusions, as well as oral loads, have generated conflicting results: a decrease [5,6,13], an increase [4,7,14,15] or no effect [8], Intrajejunal [16, 17] or intraileal [19] infusions were found to decrease the EPS. Using two different rat models, we found that only stimulations were obtained after ID hyperosmolar glucose solutions.…”

“…In conscious rats an increase of bicarbonate concentration and output was observed after 30% intraduodenal glucose while protein concentration and output decreased very significantly. These effects persisted after vagotomy.It is generally admitted that intestinal in fusion of isoosmolar glucose solutions does not appreciably change exocrine pancreatic secretion (EPS) [1][2][3][4]. The intraduodenal (ID) infusion of hyperosmolar glucose solutions has been reported by different authors to give different effects, including a decrease [5,6], an increase [4,7] or no effect on EPS [8], We report that hyperosmolar glucose adminis tered intraduodenally in anesthetized rats, a model with low basal pancreatic secretion, stimulates the volume of pancreatic fluid and bicarbonate output in a dose-related manner.…”