Distribution and morphology of defensive acid-secreting glands in Nudipleura (Gastropoda: Heterobranchia), with an emphasis on Pleurobranchomorpha

The phenomenon of gastric brooding and oral birth displayed by the Australian frog Rheobatrachus silus has not previously been observed in the Animal Kingdom. This report describes another example of gastric brooding in a recently discovered, closely related species, Rheobatrachus vitellinus. The stomach of a female R. vitellinus that had given birth to 22 froglets revealed morphologic changes which were quite different to those described in R. silus. Unlike the atrophy of the mucosa and acid-secreting oxyntic cells in the latter species, there was no evidence of major structural changes in the brooding stomach of R. vitellinus. Furthermore, no differences were observed in the light microscopic appearances of the stomach in the brooding female and that from a non-brooding female and male R. vitellinus. A striking finding not observed in the non-brooding stomachs of R. vitellinus nor in R. silus was the presence of widespread and numerous apoptotic bodies in the gastric epithelium. The apoptotic bodies were recognized as phagocytosed fragments of eosinophilic cytoplasm and pyknotic nuclear material. Ultrastructurally, well preserved organelles were observed in the phagocytosed fragments. This diffuse deletion of cells and the striking absence of major structural changes in the brooding stomach may indicate a dichotomy in the evolution of this bizarre and unique reproductive habit.

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The Gastric H/K ATPase β Subunit Gene and Transcriptional Pathways in Acid-Secreting Epithelia of the Stomach and Kidney

Molecular and Cellular Mechanisms of H+ Transport ◽

10.1007/978-3-642-79301-1_2 ◽

1994 ◽

pp. 11-18

Author(s):

Ian R. van Driel ◽

Paul A. Gleeson ◽

Seong-Seng Tan ◽

Ban-Hock Toh

Keyword(s):

Β Subunit ◽

Subunit Gene ◽

Acid Secreting

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Transcriptional profiling of gastrin-regulated genes in mouse stomach

Physiological Genomics ◽

10.1152/physiolgenomics.00176.2006 ◽

2007 ◽

Vol 29 (1) ◽

pp. 1-12 ◽

Cited By ~ 14

Author(s):

Renu N. Jain ◽

Linda C. Samuelson

Keyword(s):

Acid Secretion ◽

Gastric Acid ◽

Parietal Cell ◽

Transcriptional Profiling ◽

Cell Types ◽

Polymerase Chain Reaction Analysis ◽

Ecl Cell ◽

Severe Impairment ◽

Basal Acid ◽

Acid Secreting

Gastrin, a potent stimulator of gastric acid secretion, primarily targets the acid-secreting parietal cells and histamine-secreting enterochromaffin-like (ECL) cells in the stomach. Accordingly, gastrin-deficient (GAS-KO) mice have a severe impairment in acid secretion. The aim of this study was to characterize changes in gene expression in GAS-KO mice to identify gastrin-regulated genes and to gain insight into how gastric cell types are regulated by gastrin and acid secretion. Affymetrix microarray analysis of GAS-KO and wild-type mice identified numerous differentially expressed transcripts. The results were compared with GAS-KO mice treated with gastrin to identify genes that were gastrin responsive. Finally, genes that were primarily changed due to gastrin and not hypochlorhydria were identified by comparison to mice that are deficient in both gastrin and cholecystokinin (GAS/CCK-KO), since these mice have restored basal acid secretion. The data were validated by quantitative reverse transcriptase polymerase chain reaction analysis. Interestingly, a number of inflammatory response genes were induced in GAS-KO mice and normalized in GAS/CCK-KO mice, suggesting that they were increased in response to low gastric acid. Moreover, a number of parietal cell transcripts that were downregulated in GAS-KO mice were similarly restored in GAS/CCK-KO mice, suggesting that parietal cell changes were also primarily associated with hypochlorhydria. In contrast, ECL cell genes that were markedly downregulated in GAS-KO mice continued to be reduced in GAS/CCK-KO mice, demonstrating that gastrin coordinately regulates a number of ECL cell genes, including several involved in histamine synthesis and secretion.

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Purification of Gastric Mucosal ECL Cells from a Crude Elutriation Fraction

The Scientific World JOURNAL ◽

10.1100/tsw.2002.852 ◽

2002 ◽

Vol 2 ◽

pp. 1643-1645 ◽

Cited By ~ 1

Author(s):

John Graham

Keyword(s):

Gastric Mucosa ◽

Ion Transport ◽

Parietal Cell ◽

Cell Function ◽

Parietal Cells ◽

Centrifugal Elutriation ◽

Ecl Cells ◽

Acid Secreting ◽

Density Barrier

Acid-secreting parietal cells from the gastric mucosa are widely studied as a model in studies on ion transport and the endocrine/paracrine ECL cells effectively control parietal cell function. Discontinuous gradients of iodixanol for the purification of ECL cells were subsequently simplified to the use of a density barrier. This technique is now commonly used following initial centrifugal elutriation.

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Reduced Pepsin A Processing of Sonic Hedgehog in Parietal Cells Precedes Gastric Atrophy and Transformation

Journal of Biological Chemistry ◽

10.1074/jbc.m707090200 ◽

2007 ◽

Vol 282 (46) ◽

pp. 33265-33274 ◽

Cited By ~ 49

Author(s):

Yana Zavros ◽

Meghna Waghray ◽

Arthur Tessier ◽

Longchuan Bai ◽

Andrea Todisco ◽

...

Keyword(s):

Gene Expression ◽

Sonic Hedgehog ◽

Parietal Cell ◽

Human Stomach ◽

Gastric Atrophy ◽

Parietal Cells ◽

Tissue Extracts ◽

Neoplastic Lesion ◽

Acid Secreting ◽

Normal Stomach

Sonic hedgehog (Shh) is not only essential to the development of the gastrointestinal tract, but is also necessary to maintain the characteristic acid-secreting phenotype of the adult stomach. Gastrin is the only hormone capable of stimulating gastric acid and is thus required to maintain functional parietal cells. We have shown previously that gastrin-null mice display gastric atrophy and metaplasia prior to progression to distal, intestinal-type gastric cancer. Because reduced levels of Shh peptide correlate with gastric atrophy, we examined whether gastrin regulates Shh expression in parietal cells. We show here that gastrin stimulates Shh gene expression and acid-dependent processing of the 45-kDa Shh precursor to the 19-kDa secreted peptide in primary parietal cell cultures. This cleavage was blocked by the proton pump inhibitor omeprazole and mediated by the acid-activated protease pepsin A. Pepsin A was also the protease responsible for processing Shh in tissue extracts from human stomach. By contrast, extracts prepared from neoplastic gastric mucosa had reduced levels of pepsin A and did not process Shh. Therefore processing of Shh in the normal stomach is hormonally regulated, acid-dependent, and mediated by the aspartic protease pepsin A. Moreover parietal cell atrophy, a known pre-neoplastic lesion, correlates with loss of Shh processing.

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NH4+ transport in acid-secreting insect epithelium

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1988.254.2.r348 ◽

1988 ◽

Vol 254 (2) ◽

pp. R348-R356 ◽

Cited By ~ 6

Author(s):

R. B. Thomson ◽

J. M. Thomson ◽

J. E. Phillips

Keyword(s):

Amino Acids ◽

Apical Membrane ◽

Schistocerca Gregaria ◽

Hydrogen Ion ◽

Ph Gradients ◽

Ussing Chambers ◽

Ion Secretion ◽

Acid Secreting ◽

Ph Range ◽

The Relationship

The relationship between ammonia secretion (JAmm), hydrogen ion secretion (JH), and intracellular pH (pHi) was investigated in isolated locust (Schistocerca gregaria) rectal epithelia mounted as flat sheets in specially designed Ussing chambers. In the absence of exogenous CO2 and ammonia, the rectum is capable of net acid and ammonia secretion into the lumen against pH gradients of up to 1.8 U. JAmm was dependent on the presence of luminal amino acids and Na+ and it was relatively unaffected by K+ removal or changes in membrane potential. JAmm and pHi remained fairly constant over a luminal pH range of 7-5, whereas JH decreased linearly to zero over the same pH range. Mucosal addition of 1 mM amiloride reduced JAmm by 60%. This study demonstrates that the locust rectum secretes significant quantities of endogenously produced ammonia preferentially into the lumen as NH+4 rather than NH3. Moreover, the results suggest that the ammonia crosses the apical membrane via an amiloride-inhibitable Na+-NH+4 exchange mechanism.

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Localized Suppression of Inflammation at Sites of Helicobacter pylori Colonization

Infection and Immunity ◽

10.1128/iai.05602-11 ◽

2011 ◽

Vol 79 (10) ◽

pp. 4186-4192 ◽

Cited By ~ 16

Author(s):

Alison L. Every ◽

Garrett Z. Ng ◽

Caroline D. Skene ◽

Stacey N. Harbour ◽

Anna K. Walduck ◽

...

Keyword(s):

Helicobacter Pylori ◽

Potential Model ◽

Gastric Ph ◽

Male Mice ◽

Wild Type ◽

Content Type ◽

Female Mice ◽

Gastric Corpus ◽

Acid Secreting ◽

H Pylori

ABSTRACTWhile gastric adenocarcinoma is the most serious consequence ofHelicobacter pyloriinfection, not all infected persons develop this pathology. Individuals most at risk of this cancer are those in whom the bacteria colonize the acid-secreting region of the stomach and subsequently develop severe inflammation in the gastric corpus. It has been reported anecdotally that male mice become infected with greater numbers ofH. pyloribacteria than female mice. While investigating this phenomenon, we found that increasedH. pyloriinfection densities in male mice were not related to antibody production, and this phenomenon was not normalized by gonadectomy. However, the gastric pH in male 129/Sv mice was significantly elevated compared with that in female mice. Differences in colonization were evident within 1 day postinfection and significantly arose due to colonization of the gastric corpus region in male mice. This provided a potential model for comparing the effect of corpus colonization on the development of gastritis. This was explored using two models ofH. pylori-induced inflammation, namely, 2-month infections ofMuc1−/−mice and 6-month infections of wild-type 129/Sv mice. WhileH. pyloriinfection of female mice induced a severe, corpus-predominant atrophic gastritis, to our surprise, male mice developed minimal inflammation despite being colonized with significantly moreH. pyloribacteria than female controls. Thus, colonization of the gastric corpus in male mice was associated with a loss of inflammation in that region. The suppression of inflammation concomitant with infection of the gastric corpus in male mice demonstrates a powerful localized suppression of inflammation induced at sites ofH. pyloricolonization.

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Functional regulation of H+-ATPase-rich cells in zebrafish embryos acclimated to an acidic environment

AJP Cell Physiology ◽

10.1152/ajpcell.00576.2008 ◽

2009 ◽

Vol 296 (4) ◽

pp. C682-C692 ◽

Cited By ~ 56

Author(s):

Jiun-Lin Horng ◽

Li-Yih Lin ◽

Pung-Pung Hwang

Keyword(s):

Single Cells ◽

Cell Number ◽

Alveolar Type ◽

Zebrafish Embryos ◽

Ph Homeostasis ◽

Epithelial Stem Cells ◽

Acid Secreting ◽

Functional Regulation ◽

Cell Acid ◽

Apical Opening

It is important to maintain internal pH homeostasis in biological systems. In our previous studies, H+-ATPase-rich (HR) cells were found to be responsible for proton secretion in the skin of zebrafish embryos during development. In this study, zebrafish embryos were exposed to acidic and basic waters to investigate the regulation of HR cell acid secretion during pH disturbances. Our results showed that the function of HR cells on the skin of zebrafish embryos can be upregulated in pH 4 water not only by increasing the cell number but also by enlarging the acid-secreting function of single cells. We also identified an “alveolar-type” apical opening under scanning electron microscopy observations of the apical membrane of HR cells, and the density and size of the alveolar type of apical openings were also increased in pH 4 water. p63 and PCNA immunostaining results also showed that additional HR cells in pH 4 water may be differentiated not only from ionocyte precursor cells but also newly proliferating epithelial stem cells.

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Ultrastructure of organic acid secreting trichomes of chickpea (Cicer arietinum)

Canadian Journal of Botany ◽

10.1139/b89-344 ◽

1989 ◽

Vol 67 (9) ◽

pp. 2669-2677 ◽

Cited By ~ 18

Author(s):

Mark D. Lazzaro ◽

William W. Thomson

Keyword(s):

Endoplasmic Reticulum ◽

Granular Material ◽

Organic Acid ◽

Cicer Arietinum ◽

Basal Cell ◽

Fixed Carbon ◽

Mesophyll Cells ◽

Dense Cytoplasm ◽

Acid Secreting ◽

Organic Acid Secretion

The acid-secreting trichomes of chickpea (Cicer arietinum L.) were composed of 18 cells, including 1 basal cell, 3 elongate stalk cells, and 14 head cells. A subcuticular secretion chamber with cuticular pores was present above the head cells at the trichome tip. The basal and stalk cells had large central vacuoles, endoplasmic reticulum, mitochondria, and small vacuoles. In the stalk cells, these small vacuoles were aligned along microtubles extending from the bottom to the top of the cells. Head cells had more dense cytoplasm than stalk cells and also had numerous mitochondria and small vacuoles. A labyrinth of tubules and vesicles at the edges of the head cells contained granular material similar to that observed in the extraplasmic space of the head cell and in the secretion chamber. In older head cells, the tubules were thinner and lacked granular material, the cells contained sequestering membranes and vacuoles, and calcium oxalate crystals were observed in the extraplasmic space. Plasmodesmata were not observed between the basal cell and the surrounding mesophyll cells, although numerous plasmodesmata with associated desmotubules and endoplasmic reticulum connected the trichome cells. Chloroplasts were not observed in the head or stalk cells, whereas the basal cell had small chloroplasts with reduced thylakoid networks and the mesophyll cells had large chloroplasts with well-developed thylakoids that may provide the fixed carbon for organic-acid secretion.

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Differentiation of the Gastric Mucosa II. Role of gastrin in gastric epithelial cell proliferation and maturation

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00172.2006 ◽

2006 ◽

Vol 291 (5) ◽

pp. G762-G765 ◽

Cited By ~ 37

Author(s):

Renu N. Jain ◽

Linda C. Samuelson

Keyword(s):

Genetically Engineered ◽

Gastric Epithelial Cells ◽

Balanced Growth ◽

Cellular Targets ◽

Genetically Engineered Mouse Models ◽

Gastric Physiology ◽

Ecl Cell ◽

Acid Secreting ◽

And Function

Gastrin is the principal hormonal inducer of gastric acid secretion. The cellular targets for gastrin in the stomach are the acid-secreting parietal cell and histamine-producing enterochromaffin-like (ECL) cell. Gastrin is also a growth factor, with hypergastrinemia resulting in increased proliferation of gastric progenitor cells and a thickened mucosa. This review presents insights into gastrin function revealed by genetically engineered mouse models, demonstrating a new role for gastrin in the maturation of parietal and ECL cells. Thus, gastrin regulates many aspects of gastric physiology, with tight regulation of gastrin levels required to maintain balanced growth and function of gastric epithelial cells.

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