Effects of aspirin on pathways of ion permeation in Necturus antrum: Role of nutrient HCO3−

Soybel, David I.; Davis, Marion B. E.; West, A. Brian

doi:10.1016/0016-5085(92)91167-3

Cited by 3 publications

(1 citation statement)

References 19 publications

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“…25,26,36,37 Drugs that are weak acids permeate and damage the epithelial cells more at lower luminal pH than in an alkaline environment. 38–40 Epithelial wound healing requires an alkaline surface pH both in the upper GI tract and in the colon. 25,26,41 Alkaline phosphatase ectoenzymatic activity is highly pH-sensitive and has recently been implicated in mucosal defense.…”

Section: Discussionmentioning

confidence: 99%

Loss of downregulated in adenoma (DRA) impairs mucosal HCO3− secretion in murine ileocolonic inflammation

Xiao

Juric

et al. 2012

Inflammatory Bowel Diseases

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Background Ileocolonic luminal pH has been reported to be abnormally low in inflammatory bowel disease (IBD) patients, and one of the causative factors may be reduced epithelial HCO3− secretory rate (JHCO3−). Disturbances in JHCO3− may occur due to inflammation-induced changes in the crypt and villous architecture, or due to the effect of proinflammatory cytokines on epithelial ion transporters. Methods To discriminate between these possibilities, the tumor necrosis factor alpha (TNF-α) overexpressing (TNF+/ΔARE) mouse model was chosen, which displays high proinflammatory cytokine levels in both ileum and colon, but develops only mild colonic histopathology and diarrhea. HCO3− secretion, mRNA expression, immunohistochemistry, and fluid absorptive capacity were measured in ileal and mid-colonic mucosa of TNF+/ΔARE and wildtype (WT) (TNF+/+) mice in Ussing chambers, and in anesthetized mice in vivo. Results The high basal JHCO3− observed in WT ileal and mid-colonic mucosa were luminal C1−-dependent and strongly decreased in TNF+/ΔARE mice. Downregulated in adenoma (DRA) mRNA and protein expression was strongly decreased in TNF+/ΔARE ileocolon, whereas cystic fibrosis transmembrane conductance regulator (CFTR), Na+/H+ exchanger 3 (NHE3), Na+/HCO3− cotransporter (NBC), and epithelial sodium channel (ENaC) expression was not significantly altered. This indicates that the severe defect in ileocolonic JHCO3− was due to DRA downregulation. Fluid absorption was severely depressed in the ileum but only mildly affected in the mid-distal colon, preventing the development of overt diarrhea. Conclusions Even mild ileocolonic inflammation may result in a decrease of epithelial HCO3− secretion, which may contribute to alterations in surface pH, intestinal flora, and mucus barrier properties.

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Section: Discussionmentioning

confidence: 99%

Loss of downregulated in adenoma (DRA) impairs mucosal HCO3− secretion in murine ileocolonic inflammation

Xiao

Juric

et al. 2012

Inflammatory Bowel Diseases

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Anesthesia and Analgesia in Nontraditional Laboratory Animal Species

Schaeffer¹

1997

Anesthesia and Analgesia in Laboratory Animals

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Identification and functional assay of an extracellular calcium-sensing receptor in Necturusgastric mucosa

Cima¹,

Cheng²,

Klingensmith³

et al. 1997

American Journal of Physiology-Gastrointestinal and Liver Physi

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In mammals and amphibians, increases in extracellular Ca2+ can activate bicarbonate secretion and other protective functions of gastric mucosa. We hypothesized that the recently cloned extracellular Ca2+-sensing receptor (CaR) is functioning in the gastric mucosa. In Necturus maculosus gastric mucosa, reverse transcription-polymerase chain reaction using primers based on previously cloned CaR sequences amplified a 326-bp DNA fragment that had 84% nucleotide sequence identity with the rat kidney CaR. Immunohistochemical localization of the CaR using specific anti-CaR antiserum revealed its presence on the basal aspect of gastric epithelial cells. In microelectrode studies of Necturus antral mucosa, exposure to elevated Ca2+ (4.8 mM) and the CaR agonists NPS-467 and neomycin sulfate resulted in significant hyperpolarizations of basal membrane electrical potentials and increases in apical-to-basal membrane resistance ratios. Circuit analysis revealed that these changes reflected specific decreases in basolateral membrane resistance. Inhibition of prostaglandin synthesis using indomethacin significantly attenuated these effects. We conclude that the CaR is present and functioning in Necturus gastric antrum.

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Effects of aspirin on pathways of ion permeation in Necturus antrum: Role of nutrient HCO3−

Cited by 3 publications

References 19 publications

Loss of downregulated in adenoma (DRA) impairs mucosal HCO3− secretion in murine ileocolonic inflammation

Loss of downregulated in adenoma (DRA) impairs mucosal HCO3− secretion in murine ileocolonic inflammation

Anesthesia and Analgesia in Nontraditional Laboratory Animal Species

Identification and functional assay of an extracellular calcium-sensing receptor in Necturusgastric mucosa

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