Molecular Dissection of HCl Secretion in Gastric Parietal Cells Using Streptolysin O Permeabilization

2008 ◽  
pp. 217-226 ◽  
Author(s):  
Xia Ding ◽  
Fang Wu ◽  
Zhen Guo ◽  
Xuebiao Yao
Keyword(s):  
Parietal Cells ◽  
Molecular Dissection ◽  
Streptolysin O ◽  
Hcl Secretion ◽  
Gastric Parietal Cells

Gastric parietal cell H(+)-K(+)-ATPase microsomes are associated with isoforms of ankyrin and spectrin

1993 ◽  
Vol 264 (1) ◽  
pp. C63-C70 ◽  
Author(s):  
P. R. Smith ◽  
A. L. Bradford ◽  
E. H. Joe ◽  
K. J. Angelides ◽  
D. J. Benos ◽  
...  
Keyword(s):  
Apical Membrane ◽  
Immunoblot Analysis ◽  
Cytoskeletal Proteins ◽  
Parietal Cells ◽  
Apical Surface ◽  
Gastric Parietal Cell ◽  
Apical Domain ◽  
Hcl Secretion ◽  
Gastric Parietal Cells ◽  
Stimulation Of

Stimulation of HCl secretion by gastric parietal cells requires the fusion of cytoplasmic H(+)-K(+)-ATPase-bearing tubulovesicles with the apical membrane. This insertion of membrane results in a dramatic increase in apical surface area through the formation of microvilli. To elucidate the elements that may stabilize the newly inserted H(+)-K(+)-ATPase within the apical membrane, we searched for specific cytoskeletal proteins associating with the gastric enzyme. We document by immunoblot analysis that ankyrin, spectrin, and actin copurify with H(+)-K(+)-ATPase microsomes prepared from gastric parietal cells. Coprecipitation of 125I-labeled native erythrocyte ankyrin with the H(+)-K(+)-ATPase from gastric microsomes using anti-H(+)-K(+)-ATPase antibodies suggests that ankyrin associates with the H(+)-K(+)-ATPase. Indirect immunofluorescence and confocal microscopy show that ankyrin and H(+)-K(+)-ATPase cosegregate within resting and secreting parietal cells. Taken together, these data suggest that the association of the gastric H(+)-K(+)-ATPase with spectrin and actin is mediated by ankyrin and that this interaction contributes to the maintenance of the polarized distribution of the enzyme to the apical domain of gastric parietal cells during acid secretion.

La3+ and pH sensitivity of Ca2+ entry and intracellular store filling in gastric parietal cells

1995 ◽  
Vol 269 (5) ◽  
pp. G770-G778 ◽  
Author(s):  
P. A. Negulescu ◽  
T. E. Machen
Keyword(s):  
Positive Feedback ◽  
Low Ph ◽  
Parietal Cells ◽  
Additional Increase ◽  
Cholinergic Agonist ◽  
Intracellular Store ◽  
Entry Pathway ◽  
Signaling Function ◽  
Previously Treated ◽  
Gastric Parietal Cells

The fluorescent Ca2+ indicator fura 2 was used to measure cytosolic free [Ca2+] ([Ca2+]i) in order to obtain information about relative rates of Ca2+ influx into parietal cells during treatment with carbachol (a cholinergic agonist) or thapsigargin (TG, a Ca(2+)-mobilizing agent) or during reloading of the internal Ca2+ stores. In Ca(2+)-containing solutions, carbachol-, TG-, and reloading-stimulated Ca2+ entry exhibited nearly identical sensitivity to La3+ [inhibition constant (Ki) approximately 10 microM] or low pH (pKi approximately 7.0). In experiments in which carbachol and TG were used, there was no additional increase in [Ca2+]i when TG was added to carbachol-treated cells or when carbachol was added to cells previously treated with TG. Thus it is likely that a single Ca2+ entry pathway serves a signaling function as well as a role in refilling the Ca2+ store during reloading. Because the Ca2+ pathway is exquisitely sensitive to pH and serosal pH increases during stimulant-induced H+ secretion (which is activated by increases in [Ca2+]i), this mechanism will exert positive feedback on parietal cells in the intact stomach. When parietal cells were pretreated with carbachol in Ca(2+)-free solutions, reloading was independent of pH and La3+, suggesting that Ca(2+)-containing solutions should be used to determine the properties of the influx pathway.

scholarly journals Receptor-operated Ca2+ channels in gastric parietal cells: gastrin and carbachol induce Ca2+ influx in depleting intracellular Ca2+ stores

1993 ◽  
Vol 289 (1) ◽  
pp. 117-124 ◽  
Author(s):  
S Roche ◽  
J P Bali ◽  
R Magous
Keyword(s):  
Steady State ◽  
Receptor Activation ◽  
Parietal Cells ◽  
The Other ◽  
Bivalent Cation ◽  
Gtp Binding ◽  
Gastric Parietal Cells ◽  
Type Receptor ◽  
Ca2 Channels ◽  
Stimulation Of

The mechanism whereby gastrin-type receptor and muscarinic M3-type receptor regulate free intracellular Ca2+ concentration ([Ca2+]i) was studied in rabbit gastric parietal cells stimulated by either gastrin or carbachol. Both agonists induced a biphasic [Ca2+]i response: a transient [Ca2+]i rise, followed by a sustained steady state depending on extracellular Ca2+. Gastrin and carbachol also caused a rapid and transient increase in Mn2+ influx (a tracer for bivalent-cation entry). Pre-stimulation of cells with one agonist drastically decreased both [Ca2+]i increase and Mn2+ influx induced by the other. Neither diltiazem nor pertussistoxin treatment had any effect on agonist-stimulated Mn2+ entry. Thapsigargin, a Ca(2+)-pump inhibitor, induced a biphasic [Ca2+]i increase, and enhanced the rate of Mn2+ entry. Preincubation of cells with thapsigargin inhibits the [Ca2+]i increase as well as Mn2+ entry stimulated by gastrin or by carbachol. Thapsigargin induced a weak but significant increase in Ins(1,4,5)P3 content, but this agent had no effect on the agonist-evoked Ins(1,4,5)P3 response. In permeabilized parietal cells, Ins(1,4,5)P3 and caffeine caused an immediate Ca2+ release from intracellular pools, followed by a reloading of Ca2+ pools which can be prevented in the presence of thapsigargin. We conclude that (i) gastrin and carbachol mobilize common Ca2+ intracellular stores, (ii) Ca2+ permeability secondary to receptor activation involves neither a voltage-sensitive Ca2+ channel nor a GTP-binding protein from the G1 family, and (iii) agonists regulate common Ca2+ channels in depleting intracellular Ca2+ stores.

Secretion of gastric parietal cells

1958 ◽  
Vol 14 (6) ◽  
pp. 204-205 ◽  
Author(s):  
D. Birnbaum ◽  
M. Wolman
Keyword(s):  
Parietal Cells ◽  
Gastric Parietal Cells

Whole-cell K+ current activation in response to voltages and carbachol in gastric parietal cells isolated from guinea pig

1991 ◽  
Vol 124 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Tohru Kotera ◽  
Akira Hashimoto ◽  
Shunji Ueda ◽  
Yasunobu Okada
Keyword(s):  
Guinea Pig ◽  
Parietal Cells ◽  
Whole Cell ◽  
Current Activation ◽  
K Current ◽  
Gastric Parietal Cells

scholarly journals Polarized Distribution of IQGAP Proteins in Gastric Parietal Cells and Their Roles in Regulated Epithelial Cell Secretion

2003 ◽  
Vol 14 (3) ◽  
pp. 1097-1108 ◽  
Author(s):  
Rihong Zhou ◽  
Zhen Guo ◽  
Charles Watson ◽  
Emily Chen ◽  
Rong Kong ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Actin Cytoskeleton ◽  
Acid Secretion ◽  
Rho Gtpase ◽  
Apical Membrane ◽  
Basolateral Membrane ◽  
Parietal Cells ◽  
Actin Dynamics ◽  
Cell Secretion ◽  
Gastric Parietal Cells

Actin cytoskeleton plays an important role in the establishment of epithelial cell polarity. Cdc42, a member of Rho GTPase family, modulates actin dynamics via its regulators, such as IQGAP proteins. Gastric parietal cells are polarized epithelial cells in which regulated acid secretion occurs in the apical membrane upon stimulation. We have previously shown that actin isoforms are polarized to different membrane domains and that the integrity of the actin cytoskeleton is essential for acid secretion. Herein, we show that Cdc42 is preferentially distributed to the apical membrane of gastric parietal cells. In addition, we revealed that two Cdc42 regulators, IQGAP1 and IQGAP2, are present in gastric parietal cells. Interestingly, IQGAP2 is polarized to the apical membrane of the parietal cells, whereas IQGAP1 is mainly distributed to the basolateral membrane. An IQGAP peptide that competes with full-length IQGAP proteins for Cdc42-binding in vitro also inhibits acid secretion in streptolysin-O-permeabilized gastric glands. Furthermore, this peptide disrupts the association of IQGAP and Cdc42 with the apical actin cytoskeleton and prevents the apical membrane remodeling upon stimulation. We propose that IQGAP2 forms a link that associates Cdc42 with the apical cytoskeleton and thus allows for activation of polarized secretion in gastric parietal cells.

scholarly journals Distribution of F-actin, fodrin, and ankyrin in gastric parietal cells of the rat.

1989 ◽  
Vol 22 (6) ◽  
pp. 593-603 ◽  
Author(s):  
M. MIZUNO ◽  
T. FUJIMOTO ◽  
K. OGAWA
Keyword(s):  
Parietal Cells ◽  
Gastric Parietal Cells
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