Zusammenfassung
Der Einfluß von Sekretin und von Cholecystokinin Oktapeptid (CCK8) auf den exokrinen Pankreas während einer vagalen Kälteblockierung beim präruminanten Kalb
Sechs 5‐Tage alte präruminante Kälber erhielten auf chirurgischem Wege ein Pankreas‐Katheter und eine Jejunal‐Kanüle, um die Rolle der extrinsischen vagalen Innervation auf die Sekretin‐ und CCK8‐beeinflußte exokrine Pankreasfunktion zu ermitteln. Zur zeitweisen, reversiblen Kälteblockierung wurden Hitzesensoren in die Vagi bilaterale eingesetzt. Die kurzzeitige, reversible Blockierung der extrinsischen vagalen Innervation führte zu einem signifikanten Anstieg des Pankreassaftvolumens mit erhöhten Protein‐ und Trypsin‐Gehalten. Die Kälteblockierung unterbindet den stimulatorischen Effekt von Sekretin auf die exokrine Pankreassekretion und unterdrückt zur gleichen Zeit die Wirkung von CCK8 und CCK8 + Sekretin. Aus den Ergebnissen läßt sich ableiten, daß die Wirkung von Sekretin auf den exokrinen Pankreas von der extrinsischen vagalen Innervierung abhängig ist. Dagegen erweist sich CCK8 teilweise als unabhängig davon, obwohl sich die Wirkung durch ihre Gegenwart potenziert.
SUMMARYFour calves were prepared surgically to investigate the exocrine pancreatic function in chronic experiments. Cooling devices were implanted on both vagi for temporary, reversible, thermal blockade of the conductivity in the nerves. Cooling of the vagi caused significant decreases of volume, total protein content and trypsin activity in pancreatic juice. All of these variables recovered to the control level immediately after the cooling. Results presented indicate an important role of vagally driven information on the exocrine pancreatic secretion in calves.
SUMMARYThe effects of local and peripheral administration of cholecystokinin-8 (CCK-8) and vasoactive intestinal polypeptide (VIP) on basal pancreatic secretion were investigated in conscious pigs. Five pigs (20 + 2 kg, mean + S.E.M.) were chronically fitted with a T-shaped cannula in the duodenum, and catheters in the pancreatic duct, jugular vein, and right gastroepiploic artery. The arterial catheter was inserted against the bloodstream with its tip opposite the duodenal branch(es) of the right gastroepiploic artery, so that all injected peptides would reach the duodenal arterial circulation excluding the pancreas. Pancreatic secretion during basal conditions (i.e. after an overnight fast) exhibited a characteristic cyclic pattern (cycle duration, 70 + 4.2 min). Secretion volume oscillated between 0.2 + 0-04 and 4 0 + 0 9 ml kg-' h-' (P < 0.001), trypsin output between 9 6 + 1.9 and 29-1 + 4-1 U kg-' h-1 (P < 0.001) and protein output between 0-36 + 0 08 and 9-2 + 1 7 mg kg-1 h-' (P < 0.001). Infusion into the jugular vein for 1 min, during the trough of pancreatic secretion, of either CCK-8 (15 pmol kg-' min-') or VIP (7 pmol kg-' min-') did not stimulate pancreatic secretion. However, local infusion of an identical dose of CCK-8 or VIP into the duodenal arterial circulation increased the volume, protein output and trypsin output of the pancreatic juice (P < 0.05 to < 0.001). These results indicate that CCK-8 and VIP can stimulate the exocrine pancreas by a duodenally mediated mechanism.
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