Wyniki wyszukiwania

1

Reefs in experimental gastroenterology - cyclic activities of the gastrointestinal tract

100%

Zabielski R.

Journal of Physiology and Pharmacology. Supplement

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2004

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tom 55

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nr 2

19-32

The activity of the upper gastrointestinal tract is periodic. It concerns the gastrointestinal and gallbladder motility, gastrointestinal blood flow, gastric, intestinal, pancreatic and biliary secretions, rate of nutrient absorption, and many other physiological events. Nowadays, the periodic activity of the gastrointestinal tract is considered as a basic physiological pattern in conscious animals and humans. Unfortunately, there are considerable species- and age-related as well as individual differences, therefore experimental protocols should consider first describing the individual periodic pattern in the examined animals. A lot of confusion may appear with data interpretation if the periodic activity is neglected, in particular when low physiological-like doses of test substances are used. For instance, the effect of CCK or VIP administration on the exocrine pancreas may differ from negligible effect to strong one depending of the phase of pancreatic secretion. The action of secretagogues on the gastrointestinal tract will also be discussed in terms of the ultradian and circadian cycles.

2

Luminal CCK and its neuronal action on exocrine pancreatic secretion

72%

Zabielski R.

Journal of Physiology and Pharmacology. Supplement

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2003

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tom 54

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nr 4

81-94

Gut regulatory peptides are produced by mucosal endocrine cells and released both into the circulation as well as into the gut lumen. Following stimulation the distribution between the circulation and gut lumen changes in favor of the gut lumen. In the blood plasma, the biological half-life of gut regulatory peptides is counted in single minutes due to high aminopeptidase activity and liver extraction. In the gut lumen, however, regulatory peptides retain their biological activity much longer, especially in newborn and young animals. A series of studies was performed in neonatal calves and pigs to explore the role of luminal cholecystokinin (CCK) on the regulation of exocrine pancreatic secretion. In anaesthetized neonatal calves, CCK was secreted into the duodenal lumen, and electrical vagal stimulation increased CCK release into the duodenal lumen but not into the circulating blood. In conscious calves, luminal CCK-8 stimulated pancreatic protein secretion by a neurohormonal mechanism dependent on a duodenal mucosal CCK1 receptor and vagal nerve activity. Immunocytochemistry pointed to an association of mucosal CCK1 and CCK2 receptors with neuronal components in the small intestine of neonatal calves. Experiments in calves and pigs with CCK-8 infusions into the duodenal branches of the right gastroepiploic artery confirmed the results of luminal CCK-8 and questioned the physiological relevance of a direct mechanism of CCK on the pancreatic acini.

3

Development and regulation of pancreatic juice secretion in cattle. State-of-the-art

72%

Zabielski R., Pierzynowski S. G.

Journal of Animal and Feed Sciences

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2001

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tom 10

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nr 1

4

Gastrointestinal tract and digestion in the young ruminant: ontogenesis, adaptations, consequences and manipulations

58%

Guilloteau P., Zabielski R., Blum J. W.

Journal of Physiology and Pharmacology. Supplement

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2009

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tom 60

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nr 3

37-46

Ograniczanie wyników

3 Journal of Physiology and Pharmacology. Supplement

1 Journal of Animal and Feed Sciences

4 Zabielski R.

1 Blum J. W.

1 Guilloteau P.

1 Pierzynowski S. G.

1 2009

1 2004

1 2003

1 2001

Reefs in experimental gastroenterology - cyclic activities of the gastrointestinal tract

Luminal CCK and its neuronal action on exocrine pancreatic secretion

Development and regulation of pancreatic juice secretion in cattle. State-of-the-art

Gastrointestinal tract and digestion in the young ruminant: ontogenesis, adaptations, consequences and manipulations