Effect of vasoactive intestinal peptide on cyclic adenosine monophosphate production in enterocytes isolated from human duodenal biopsy specimens.

Smith, J. A.; Griffin, Martin; Mireylees, Stewart E.; Long, Richard

doi:10.1136/gut.31.12.1350

Cited by 11 publications

(4 citation statements)

References 26 publications

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“…More than 90% of cells isolated by the calcium chelation method employed were identified as epithelial cells, with preparations routinely containing Ͻ3% leukocytes. We have previously demonstrated that a highly purified population of enterocytes was produced using the same isolation technique and a different cytokeratin marker (30). It, therefore, seems most likely that the NOS activity measured in these preparations is derived from enterocytes with minimal or no contribution from contaminating leukocytes.…”

Section: Discussionmentioning

confidence: 99%

“…Enterocytes were isolated using a modification of a method previously described (30). Biopsies were collected and washed twice in prewarmed sterile citrate buffer (in mM: 1.5 KCl, 96 NaCl, 27 Na citrate, 8 KH 2PO4, and 5.6 Na2HPO4, pH 7.4) before being transferred to a calcium-chelating buffer (in mM: 1.5 EDTA, 0.5 1,4-dithiothreitol, 10 NaH 2PO4, 154 NaCl) and incubated at 37°C for 30 min.…”

Section: Patientsmentioning

confidence: 99%

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Increased activity and expression of iNOS in human duodenal enterocytes from patients with celiac disease

Murray

Daniels

Coupland

et al. 2002

American Journal of Physiology-Gastrointestinal and Liver Physi

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The activity of nitric oxide synthase (NOS) was assayed in enterocytes isolated from human duodenal biopsies to determine its role in celiac disease. Patients were categorized into groups with irritable bowel syndrome, iron-deficiency anemia, B12/folate deficiency, and treated and untreated celiac disease. Enterocytes isolated from all groups showed 1400W-inhibitable Ca2+-independent NOS activity with a pH level and temperature optimum of 9.4 and 37°C, respectively. Western blotting showed that enterocytes expressed the inducible NOS protein and proteins with nitrated tyrosine residues, the latter being indicative of nitric oxide-driven peroxynitrite and/or free-radical damage. Endothelial NOS was seen only in the lamina propria. Patients with celiac disease had higher NOS activity than other patient groups. Treatment of the condition led to a fall in activity. Enzyme-linked immunosorbent assay demonstrated cGMP production by the enterocyte fraction, but cGMP levels did not correlate with NOS activity. These results suggest that inducible NOS is constitutively expressed in human duodenal enterocytes, is increased in patients with untreated celiac disease, and is partially corrected when such patients are treated. We found no evidence to support a role for nitric oxide in the formation of cGMP within the small intestine. Furthermore, we were unable to demonstrate a role for peroxynitrite/free radical damage in the pathophysiology of celiac disease.

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Section: Discussionmentioning

confidence: 99%

Section: Patientsmentioning

confidence: 99%

Increased activity and expression of iNOS in human duodenal enterocytes from patients with celiac disease

Murray

Daniels

Coupland

et al. 2002

American Journal of Physiology-Gastrointestinal and Liver Physi

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“…The neuropeptide VIP, widely distributed in specialized cells and nerves of the gut (Larsson et al 1976) and has been shown to stimulate duodenal mucosal bicarbonate secretion in the rat, cat and pig (Isenberg et al 1984, Flemstrom et al 1985 as well as in man (Wolosin et al 1989). VIP is a potent stimulator of cAMP formation in rat intestinal epithelium (Laburthe et al 1979) and in enterocytes isolated from human duodenal and jejunal biopsy specimens (Smith et al 1990, Hitchin et al 1991. However, in the cat jejunum in vivo VIP has been reported to not influence tissue cAMP concentration in villi or crypts (Eklund et al 1987).…”

Section: Discussionmentioning

confidence: 99%

Dopamine and vasoactive intestinal peptide stimulate cyclic adenosine‐3,5 ‐monophosphate formation in isolated rat villus and crypt duodenocytes

Säfsten

Flemström

1993

Acta Physiologica Scandinavica

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Secretion of bicarbonate increases the pH at the duodenal mucosal surface, a process which contributes to the protection against acid/pepsin injury. Previously, we have shown that dopaminergic compounds stimulate the duodenal bicarbonate secretion in situ, in the anaesthetized rat, through an action on peripheral dopamine D1 receptors. In order to study the possible involvement of cyclic adenosine-3',5'-monophosphate (cAMP) as an intracellular mediator in enterocytes isolated from rat duodenum, cells were collected by a combination of enzyme treatment and calcium chelation. Two major cell fractions, one mainly from villi and the other mainly of crypt origin, were studied. In the villus cell fraction, the activity of alkaline phosphatase was 1.6 +/- 0.2 mumol mg protein-1 min-1 and that of sucrase 98.8 +/- 16.4 nmol mg protein-1 min-1. In the crypt fraction, activities were 0.7 +/- 0.1 and 28 +/- 10.5, respectively. Effects of dopamine, two selective dopamine receptor agonists and vasoactive intestinal peptide (VIP) on intracellular accumulation of cAMP were examined by radio-immunoassay (RIA). In the crypt cell fraction, VIP (10(-7) M) caused an increase in cAMP which was maximal after 5 min (78 +/- 28% above control, P < 0.01). In the villus cell fraction, maximal responses to VIP (60 +/- 24% above control, P < 0.05), did not occur until after 60 min of incubation. In contrast, there were no significant differences between villi and crypt enterocytes in respect to effects of dopamine, the dopamine D1-receptor agonist SKF-38393 and the D2-receptor agonist quinpirole.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…exchange by a cAMPdependent protein kinase [22]. VIP and PGE2 were shown to act via receptors coupled to adenylate cyclase in iso lated enterocytes in the rat [23] and man [24], We have recently reported that VIP and PGE2 potently stimulate adenylate cyclase and protein kinase A in homogenized duodenal enterocytes, but secretin and PGF2(1 were only weak stimulants [21], This is consistent with the strong effects of PGE2 and VIP on duodenal bicarbonate secre tion in this study. We have recently described the pres ence on duodenal enterocytes of VIP receptors [25] and EP2 subtype receptors for PGE2 [15], All this is corrobora tive evidence for the role of cAMP in bicarbonate secre tion.…”

Section: Second Messengers O F Bicarbonate Secretionmentioning

confidence: 99%

Comparative Activities of Agonists of Active Duodenal Bicarbonate Secretion in the Guinea Pig

Odes

Muallem²,

Reimer³

et al. 1994

Digestion

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The comparative activity of agonists of duodenal bicarbonate secretion was studied in the anesthetized guinea pig, where the duodenal lumen was perfused with 24 mmol/l NaHCO₃ to ensure active secretion of bicarbonate. Agonists were infused alone and in combination. Dibutyryl 3’,5’-cyclic adenosine monophosphate, vasoactive intestinal polypeptide (VIP) and prostaglandin E₂ (PGE₂) were strong stimulants of bicarbonate secretion. Theophylline, dibutyryl 3’,5’-cyclic guanosine monophosphate, glucagon and prostaglandin F_2α (PGF_2α) were weaker agonists, and secretin had no effect. Combinations of any two of VIP, PGE₂ and glucagon depressed bicarbonate secretion, whereas combinations of PGE₂ and PGF_2α, VIP and PGE₂, and glucagon and PGF_2α increased bicarbonate secretion. The data indicate that cAMP and other secondary messengers may mediate duodenal bicarbonate secretion.

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Effect of vasoactive intestinal peptide on cyclic adenosine monophosphate production in enterocytes isolated from human duodenal biopsy specimens.

Cited by 11 publications

References 26 publications

Increased activity and expression of iNOS in human duodenal enterocytes from patients with celiac disease

Increased activity and expression of iNOS in human duodenal enterocytes from patients with celiac disease

Dopamine and vasoactive intestinal peptide stimulate cyclic adenosine‐3,5 ‐monophosphate formation in isolated rat villus and crypt duodenocytes

Comparative Activities of Agonists of Active Duodenal Bicarbonate Secretion in the Guinea Pig

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