The response of the pancreas of the anaesthetized cat to secretin before, during and after reversible vagal blockade.

Abstract

SUMMARY1. Cooling the cervical vagi of the anaesthetized splanchnectomized cat to 2 TC caused a 54-4 + 8-8 % inhibition of pancreatic electrolyte secretion stimulated submaximally with pure secretin.2. On rewarming the vagi there was a prolonged increase in secretion rate over and above the control rate which existed before cooling. The increase lasted about 90 min.3. There were no changes in acid/base status due to interference of the lung inflation reflex which could account for the inhibition of secretion and the subsequent rebound.4. Cold block of the cervical vagi increased the transpancreatic electrical conductance, indicating that vasodilation had occurred and therefore eliminated a vasomotor cause for the inhibition.5. Electrolyte secretion was also inhibited by bilateral vagal section. 6. Atropine only partially prevented the inhibitory response to vagal cooling. A cholinergic mechanism, therefore, accounted for some but not all of the response to vagal cooling.7. It is concluded that even in the fasted, anaesthetized animal vagal impulses facilitate the action of secretin on the pancreas. This facilitation is only partially cholinergic; the major part of the response is due to some non-cholinergic transmitter substance. Such a mechanism may be necessary to potentiate the action of the very small amounts of secretin which appear to be released during a meal.

Exocrine pancreatic function during cold blockade of the vagus in chronic experiments on calves

“…The effect of cold block was immediate. There was no increase in the secretion rate above control levels after rewarming in contrast to the findings of Grundy et al (1983). However, in the latter experiments, pancreatic secretion was stimulated continuously by pure secretin, even during the period of cold block, so the experiments are not directly comparable.…”

“…In an attempt to differentiate between vagal and hormonal control, both pharmacological and nerve section have been used. The effects of truncal vagotomy have been reported by many authors (Thomas, 1950 for early references; Tankel & Hollander, 1958;Magee, Fragola & White, 1965;Henriksen, 1969;Moreland & Johnson, 1971;Konturek, Becker & Thompson, 1974;Debas, Konturek & Grossman, 1975;Grundy et al 1983). In addition, pancreatic secretion has been studied after complete extrinsic denervation brought about by autotransplantation (Wang & Grossman, 1951;Singer, Solomon & Grossman, 1980;Kohler, Nustede, Barthel & Schafmayer, 1987).…”

“…The effect of section of the vagus nerves on the response of the pancreas to secretin has produced conflicting results, from an unchanged response or a reduced response to no response at all (for references see Grundy, Hutson & Scratcherd, 1983). The contribution of the vagus nerves to the control of pancreatic secretion varies from species to species (for references see Harada, Nakagawa &Kato, 1982 andSinger, 1987).…”

Effect of intraduodenal HCl and soybean extract on pancreatic juice secretion during atropinization and cold vagal blockade in calves

“…However, a CCK-A receptor antagonist inhibited the action of exogenous CCK on the exocrine pancreas without influencing the postprandial response in the dog (Pendleton, Bendesky, Schaffer, Nolan, Gould & Clineschmidt, 1987). In studies in dog, cat, calf and sheep the interdigestive secretion of pancreatic juice was suppressed by various means of vagus blockade and by blockade of the parasympathetic system (Wang & Grossman, 1951;Moreland & Johnson, 1971;Grundy, Hutson & Scratcherd, 1983;Kato, Adachi, Ando, Mineo & Ushijima, 1985;Zabielski, Podgurniak, Pierzynowski & Barej, 1990). However, the interaction between the peptides and the nerves regulating the exocrine pancreas is not fully understood.…”

A permissive role for the vagus nerves in the genesis of antro‐antral reflexes in the anaesthetized ferret.

“…In situations where the extrinsic nerves are severed but the intramural nerve plexuses are intact local reflexes provide another means for control, as is the case with gastric acid secretion from a Heidenhain pouch (see Grossman, 1981 (Grundy, Hutson & Scratcherd, 1983). In the second group of experiments the abdominal aorta was cannulated low down in the abdomen and the tip of the catheter positioned in the region of the coeliac axis to allow close arterial infusions of acetylcholine.…”