Parietal Cells Of Gastric Glands Research Articles

Epidermal growth factor receptor 2 immunoexpression in gastric cells of domestic cats with H. heilmannii infection

The aim of this study was to evaluate the immunoexpression of HER-2 in gastric cells of cats infected with Non H. pylori Helicobacter (NHPH) and to investigate an association with the presence of inflammatory infiltrate. Forty-eight paraffin-embedded gastric samples were retrieved from the archives of the Veterinary Anatomic Pathology Laboratory that had previously been shown to be positive for NHPH with the rapid urease test and cytology. Infection by NHPH was confirmed by histopathology using the Warthin-Starry staining. Hematoxylin-eosin stained sections were reviewed to evaluate inflammatory cell infiltrates. Immunohistochemical analysis was done using anti- H. pylori antibody and anti-HER-2 antibody. Molecular analysis was performed by PCR to confirm the presence of Helicobacter. Statistical analysis was performed to determine whether there was an association between the presence of H. Heilmannii and HER-2 expression in gastric samples. All samples were positive for NHPH, by immunohistochemistry, and confirmed by PCR as H. Heilmannii. On histopathologic analysis, 56,3% of the samples had lymphocytes and plasma cells infiltrates, 52,1% of which were mild and 4,2% moderate. The intensity of the inflammatory infiltrate in the gastric mucosa was significantly greater in the complete plasma membrane of parietal cells of gastric glands that had greater HER-2 immunoexpression (p = 0.0001). A statistically significant association (p = 0.007) between the H. Heilmannii infection score and the expression of HER-2 in the lateral membrane of gastric surface cells was observed. HER-2 expression may be increased in feline gastric cells infected by H. Heilmannii and in parietal cells of gastric glands with an increased inflammatory infiltrate.

Radiographic Localization Study of a Novel Potassium-Competitive Acid Blocker, Vonoprazan, in the Rat Gastric Mucosa.

Vonoprazan fumarate (TAK-438) is a novel potassium-competitive acid blocker that appears to exert a longer/more potent antisecretory effect than lansoprazole due to high accumulation/slow clearance from the gastric glands. However, there is no direct evidence that vonoprazan selectively accumulates in gastric parietal cells of gastric glands. To investigate the distribution of radioactivity in the rat stomach after single intravenous administration of [(3)H]-labeled vonoprazan. Autoradioluminography of the stomach revealed that at 5h after administration, radioactivity levels in the corpus mucosal layer was higher than radioactivity levels in the muscular layer, pylorus, and forestomach. At 24h, although overall radioactivity was significantly decreased, the highest radioactivity was still observed in the mucosal layer. Accumulation of radioactivity in gastric parietal cells was quantitatively analyzed using microautoradiography. The number of silver granules in parietal cells from vonoprazan-injected rats was higher than in cells from a saline-injected rat. At 24h, the number of granules was approximately at 20% of the number of granules at 5h. There was no clear deposition of granules in other components. At 5h, radioactivity was measured at 1.799µgEq/g in the stomach and 0.172µgEq/mL in plasma. After 24h, radioactivity had decreased to 0.584µgEq/g in the stomach and 0.078µgEq/mL in plasma. Vonoprazan selectively accumulates in gastric parietal cells in the mucosal layer of the rat stomach after intravenous administration.

Broad tissue expression of membrane progesterone receptor Alpha in normal mice

The broad tissue distribution of membrane progesterone receptor alpha (mPRalpha) in vertebrates suggests multiple physiological functions of the receptor. Current knowledge regarding the receptor distribution, however, is largely obtained via non-histological assays. In this study, the tissue distribution of mPRalpha in mice of both sexes was described using both histological and non-histological methods. Immunohistochemical analysis revealed that abundant expression of mPRalpha was consistently detected in the cytoplasm and membrane of smooth muscles in vasculatures, gastro-intestines, and uterus. It was also observed in myoepithelial cells of mammary gland and intra-ovarian myofibroblasts. These findings suggest that mPRalpha may function as a mediator of P4 in regulating function of smooth muscles or smooth muscle-like cells in numerous physiological processes such as vasodilation, transportation of contents within luminary organs, relaxation of the uterine myometrium during pregnancy, release of oocytes, and milk secretion. In addition, strong mPRalpha expression was identified in the parietal cells of gastric glands, indicating the potential roles of P4/mPRalpha signaling in the modulation of gastric acid secretion. Surprisingly, in the testis of male mice mPRalpha was mainly seen in the nuclei, rather than cytoplasm and/or membrane, of the primary and secondary spermatocytes, suggesting a direct role of the receptor in gene regulation. Our results indicate that mPRalpha may function as a key modulator of P4 in the modulation of multiple physiological functions in normal mice.

Inhibition of small-conductance Cl- channels by the interleukin-1beta-stimulated production of superoxide in rabbit gastric parietal cells.

We have shown previously that the G protein-coupled production of superoxide anion (O2-) leads to closure of small-conductance Cl- channels (0.3-0.4 pS) in the basolateral membrane of rabbit parietal cells. In the present study, effects of interleukin-1beta (IL-1beta) on the Cl- channel were investigated. In the whole-cell patch-clamp recording, IL-1beta (0.3-10 ng ml-1) inhibited the whole-cell Cl- current recorded from a parietal cell within isolated rabbit gastric glands. Variance noise analysis of the whole-cell Cl- current showed that the single channel conductance of the Cl- channel that is sensitive to IL-1beta is 0.37 pS. The IL-1beta (1 ng ml-1)-induced decrease of the Cl- current was abolished by anti-IL-1beta antibody (2 microg ml-1), recombinant IL-1 receptor antagonist (500 ng ml-1), GDPbetaS (500 microM) and superoxide dismutase (100 units ml-1), a scavenger of O2-. Northern blot analysis showed that the mRNA of the IL-1 receptor was selectively expressed in rabbit gastric parietal cells. In the dihydrofluorescein diacetate-loaded single parietal cells in gastric glands, IL-1beta (0.3-10 ng ml-1) stimulated the production of oxygen radicals. Y-27632 (1-10 microM), a specific Rho-kinase inhibitor, and fluvastatin (10 microM), an indirect inhibitor for Rho proteins, significantly inhibited the IL-1beta-induced effects on the channel activity and production of oxygen radicals. IL-1beta (0.3-10 ng ml-1) activated Rho in the parietal cells. These results indicate that IL-1beta binds to the IL-1 receptor of gastric parietal cells and inhibits the small-conductance Cl- channel via the G protein-mediated Rho/Rho-kinase-dependent production of O2-.

Inhibition of small-conductance Cl- channels by the interleukin-1beta-stimulated production of superoxide in rabbit gastric parietal cells

We have shown previously that the G protein-coupled production of superoxide anion (O2−) leads to closure of small-conductance Cl− channels (0.3–0.4 pS) in the basolateral membrane of rabbit parietal cells. In the present study, effects of interleukin-1β (IL-1β) on the Cl− channel were investigated. In the whole-cell patch-clamp recording, IL-1β (0.3–10 ng ml−1) inhibited the whole-cell Cl− current recorded from a parietal cell within isolated rabbit gastric glands. Variance noise analysis of the whole-cell Cl− current showed that the single channel conductance of the Cl− channel that is sensitive to IL-1β is 0.37 pS. The IL-1β (1 ng ml−1)-induced decrease of the Cl− current was abolished by anti-IL-1β antibody (2 μg ml−1), recombinant IL-1 receptor antagonist (500 ng ml−1), GDPβS (500 μM) and superoxide dismutase (100 units ml−1), a scavenger of O2−. Northern blot analysis showed that the mRNA of the IL-1 receptor was selectively expressed in rabbit gastric parietal cells. In the dihydrofluorescein diacetate-loaded single parietal cells in gastric glands, IL-1β (0.3–10 ng ml−1) stimulated the production of oxygen radicals. Y-27632 (1–10 μM), a specific Rho-kinase inhibitor, and fluvastatin (10 μM), an indirect inhibitor for Rho proteins, significantly inhibited the IL-1β-induced effects on the channel activity and production of oxygen radicals. IL-1β (0.3–10 ng ml−1) activated Rho in the parietal cells. These results indicate that IL-1β binds to the IL-1 receptor of gastric parietal cells and inhibits the small-conductance Cl− channel via the G protein-mediated Rho/Rho-kinase-dependent production of O2−.

Histamine Increased the Uptake of Rhodamine 123 in Mitochondria of Living Parietal Cells in Cultured Gastric Glands from Starved Guinea Pigs

We previously found that parietal cells in guinea pigs starved for a few days contained giant mitochondria while the cells of animals starved and then injected with histamine mostly did not. To test whether mitochondria change their size and activity according to energy demands for acid secretion, we examined the dynamics of mitochondria stained by rhodamine 123 in living parietal cells in gastric glands under a confocal microscope. The glands were isolated from guinea pigs starved for 60-72 hr. Because mitochondria were closely packed in the cytoplasm, we failed to observe the morphological changes of each mitochondrion in parietal cells. However, we successfully observed that 10-5 M histamine induced an increase in the fluorescence intensity (the concentration of rhodamine 123) in mitochondria in subpopulations of parietal cells; the fluorescence intensity increased sharply within minutes after the histamine administration in some cells, while it gradually increased from just after the administration in other cells. We also found that a subpopulation of mitochondria within a parietal cell responded to the secretagogue. The findings suggest that parietal cells exist as a heterogeneous population in gastric glands and contain heterogeneous mitochondria in terms of their mitochondrial response to histamine.

Colocalization of KCNQ1/KCNE channel subunits in the mouse gastrointestinal tract.

The KCNQI potassium channel alpha-subunit can associate with various KCNE beta-subunits that drastically influence channel gating. Here we show that in the mouse gastrointestinal tract KCNQ1 is prominently expressed in stomach, small intestine and colon, while KCNE3 is expressed in the colon and to a lesser extent in small intestine. Immunostaining revealed that KCNQ1 colocalizes with KCNE3 in the basolateral membranes of crypt cells of the colon and small intestine. Together with the previously shown electrophysiological properties of KCNQ1/KCNE3 channels, this strongly suggests that they form the basolateral potassium conductance that is required for transepithelial cAMP-stimulated chloride secretion. In the stomach, KCNQ1 is expressed together with the H+/K+-ATPase in the luminal membrane of acid-secreting parietal cells of gastric glands. KCNE2, but neither KCNE1 nor KCNE3 was detected in the stomach by Northern analysis. Similar to KCNQ1, KCNE2 was present in gastric glands in only a subset of cells that probably represent parietal cells. The coexpression of KCNQ1 and KCNE2 in HEK293 cells yielded potassium currents that were open at resting voltages, suggesting that these heteromeric channels may underlie the apical potassium conductance in acid-secreting parietal cells that is necessary for the recycling of potassium ions during acid secretion via the H+/K+-ATPase.

Human carbonic anhydrase isoenzyme C

The effects of some alcohol and aldehyde containing fixatives on the antigenicity of human carbonic anhydrase isoenzyme C (HCA C) were tested in order to reveal the most suitable method for the immunohistochemical localization of this enzyme. The use of 2% and 4% paraformaldehyde or 2% glutaraldehyde solutions before immunoperoxidase (PAP) staining resulted in the loss of HCA C-specific reactivity in the surface epithelial cells of human appendicular and gastric mucosae, whereas the antigenic reactivity of HCA C was well retained in the parietal cells of gastric glands. In corresponding tissue sections fixed with one of the alcohol containing solutions (abs. methanol, methanol + chloroform 2:1 or Carnoy fluid) both the surface epithelial and parietal cells showed HCA C-specific immunostaining after the PAP procedure. In addition, the antigenicity of HCA C was found to be well preserved in some tubular cells of human kidney fixed in Carnoy fluid. The paraffin infiltration at relatively low temperature did not markedly affect the enzyme antigenicity. Fixation in Carnoy fluid coupled with paraffin embedding at 55-60 degrees C in vacuo was found to give the best preservation of the antigenicity of HCA C with good morphological integrity for light microscopical localization.

Staining secretory capillaries of exocrine glands with techniques for specific phosphatases.

Intercellular secretory capillaries in parotid glands, eccrine sweat glands and intracellular secretory capillaries in parietal cells of gastric glands were demonstrated histo-chemically by the use of the Wachstein-Meisel adenosinetriphosphatase (ATPase) technique in the rabbit, rat and guinea pig. However, with the Wachstein-Meisel 5-nucleotidase technique, secretory capillaries were not stained. For parotid glands, optimal incubation in ATPase substrate mixture was: in rabbit, 15 min; in rat, 2.5 hr; and in guinea pig, 2 hr. For eccrine sweat glands, optimal incubation was 15 min in rabbit, 30 min in rat and 15 min in guinea pig. For parietal cells of gastric glands, optimal incubation was 3 hr for all three species. Secretory capillaries were best demonstrated in the parotid by using rabbit tissue; in eccrine sweat glands, with rat tissue, and in parietal cells, guinea pig tissue. Since ATPase activity in cell membranes of secretory cells may play a part in the mechanism of transport of secretory produ...