Interaction of Dietary Protein and Trypsin Inhibitor on Plasma Cholecystokinin and Pancreatic Growth in Rats

Green, Gary M.; Levan, Van H.; Liddle, Rodger A.

doi:10.1007/978-1-4757-0022-0_7

Cited by 26 publications

(10 citation statements)

References 13 publications

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“…A general, in vivo, effect of CCK injection or infusion on pancreatic enzyme secretion has been reported in the past (34,35). Besides its general effect on acinar cell secretion, caerulein specifically increased the relative synthesis of trypsin and chymotrypsin, supporting its proposed role in protease regulation in response to dietary protein (36). These effects of caerulein in vitro parallel its reported in vivo effects on pancreatic enzyme gene expression.…”

Section: Discussionsupporting

confidence: 62%

Effects of Secretin and Caerulein on Pancreatic Digestive Enzymes in Cultured Rat Acinar Cells

Hirschi

P²,

Brannon³

1994

Pancreas

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Caerulein is proposed to regulate the synthesis of pancreatic proteases and amylase. Similarly, secretin is implicated in the regulation of pancreatic lipase synthesis. Evidence of these regulations is predominantly from in vivo studies. We therefore examined the effects of caerulein and secretin directly on acinar cells to eliminate possible interactions with other regulatory factors. Cellular and media enzyme activities and relative synthesis were measured after 24 h of hormonal treatment. Cells were incubated with ['4C]-amino acids and then subjected to two-dimensional gel electrophoresis to separate individual acinar proteins for subsequent determination of incorporated radioactivity and relative synthesis. In general, all enzyme activities decreased (33%; p < 0.02) over time in culture and medium enzyme activities increased (370%; p < 0.00001) in all treatment groups. Caerulein further decreased cellular content of all enzymes (p < 0.002) and increased media amylase and lipase activities (p < 0.02). Caerulein, however, significantly increased the relative synthesis of trypsin (28%) and tended to increase that of chymotrypsin (25%; p < 0.06), which supports its proposed role in protease regulation. Secretin, on the other hand, did not significantly affect the cellular or medium activities or the relative synthesis of any pancreatic enzyme evaluated. Therefore, this study does not support the proposed role of secretin in lipase regulation.

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Section: Discussionsupporting

confidence: 62%

Effects of Secretin and Caerulein on Pancreatic Digestive Enzymes in Cultured Rat Acinar Cells

Hirschi

P²,

Brannon³

1994

Pancreas

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“…Similar explanations could be given for fish proteins [152]. As observed with trypsin inhibitors in rats [33], undigested soybean protein may form a complex with duodenal trypsin that could stimulate CCK release by activation of a trypsin-sensitive CCK-releasing factor.…”

Section: Effect Of Age On Digestive Productions and Enzyme Expressionsmentioning

confidence: 63%

Development of gastrointestinal and pancreatic functions in mammalians (mainly bovine and porcine species): influence of age and ingested food

Zabielski¹,

Huërou-Luron²,

Guilloteau³

1999

Reprod. Nutr. Dev.

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-This review summarizes recent advances in knowledge on the development of digestive tissues and their productions as well as mechanisms of regulation in response to age and ingested food in mammalian species (mainly bovine and porcine species). In the first two sections, changes are reported for stomach, pancreas and small intestine, and examined in relation to different situations (colostral, milk feeding and weaned periods). The implication of some regulatory substances (growth factors, gut regulatory peptides and neurohormonal substances) in regulation mechanisms is discussed over these periods. For

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“…Its endogenous counterpart, CCK, is elevated in the blood after a meal high in fats or proteins (20). Inhibition of gut trypsin activity also increases CCK release from intestinal endocrine cells by activating trypsin feedback regulation of CCK release (21)(22)(23). Camostat is a common trypsin inhibitor that has been widely used experimentally to increase circulating endogenous CCK.…”

Section: Figurementioning

confidence: 99%

An NF-κB pathway–mediated positive feedback loop amplifies Ras activity to pathological levels in mice

et al. 2012

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Genetic mutations that give rise to active mutant forms of Ras are oncogenic and found in several types of tumor. However, such mutations are not clear biomarkers for disease, since they are frequently detected in healthy individuals. Instead, it has become clear that elevated levels of Ras activity are critical for Ras-induced tumorigenesis. However, the mechanisms underlying the production of pathological levels of Ras activity are unclear. Here, we show that in the presence of oncogenic Ras, inflammatory stimuli initiate a positive feedback loop involving NF-κB that further amplifies Ras activity to pathological levels. Stimulation of Ras signaling by typical inflammatory stimuli was transient and had no long-term sequelae in wild-type mice. In contrast, these stimuli generated prolonged Ras signaling and led to chronic inflammation and precancerous pancreatic lesions (PanINs) in mice expressing physiological levels of oncogenic K-Ras. These effects of inflammatory stimuli were disrupted by deletion of inhibitor of NF-κB kinase 2 (IKK2) or inhibition of Cox-2. Likewise, expression of active IKK2 or Cox-2 or treatment with LPS generated chronic inflammation and PanINs only in mice expressing oncogenic K-Ras. The data support the hypothesis that in the presence of oncogenic Ras, inflammatory stimuli trigger an NF-κB-mediated positive feedback mechanism involving Cox-2 that amplifies Ras activity to pathological levels. Because a large proportion of the adult human population possesses Ras mutations in tissues including colon, pancreas, and lung, disruption of this positive feedback loop may be an important strategy for cancer prevention.

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Interaction of Dietary Protein and Trypsin Inhibitor on Plasma Cholecystokinin and Pancreatic Growth in Rats

Cited by 26 publications

References 13 publications

Effects of Secretin and Caerulein on Pancreatic Digestive Enzymes in Cultured Rat Acinar Cells

Effects of Secretin and Caerulein on Pancreatic Digestive Enzymes in Cultured Rat Acinar Cells

Development of gastrointestinal and pancreatic functions in mammalians (mainly bovine and porcine species): influence of age and ingested food

An NF-κB pathway–mediated positive feedback loop amplifies Ras activity to pathological levels in mice

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