Localization of ouabain-binding sites in frog gastric mucosa

1982 ◽  
Vol 243 (4) ◽  
pp. G297-G303
Author(s):  
H. F. Helander ◽  
R. P. Durbin
Keyword(s):  
Gastric Mucosa ◽  
Epithelial Cells ◽  
Electrical Activity ◽  
Acid Secretion ◽  
Binding Sites ◽  
Microscopic Level ◽  
Light Microscopic Level ◽  
Ouabain Binding ◽  
Oxyntic Cell ◽  
Silver Grains

Autoradiography at the light microscopic level was used to localize sites of [3H]ouabain binding in isolated stimulated frog gastric mucosa. Silver grains denoting binding were located near basal and lateral surfaces in both oxyntic and surface epithelial cells. Binding to oxyntic cells occurred well before inhibition of acid secretion, consistent with the view that inhibition by this drug is indirect, and subsequent to inactivation of oxyntic cell Na+-K+-ATPase and the resulting depression of cellular K+. The presence of Na+-K+-ATPase in surface cells, as shown by binding of labeled ouabain, suggests a role for that transport enzyme in electrical activity and secretion of alkali by these cells.

ultrastructural process of intestinal wound healing

1995 ◽  
Vol 53 ◽  
pp. 1024-1025
Author(s):  
Rick L. Vaughn ◽  
Shailendra K. Saxena ◽  
John G. Sharp
Keyword(s):  
Wound Healing ◽  
Epithelial Cells ◽  
Smooth Muscles ◽  
Microscopic Level ◽  
Light Microscopic Level ◽  
Ileal Mucosa ◽  
Wound Model ◽  
Serosal Surface ◽  
Complex Process ◽  
Orderly Fashion

We have developed an intestinal wound model that includes surgical construction of an ileo-cecal patch to study the complex process of intestinal wound healing. This allows approximation of ileal mucosa to the cecal serosa and facilitates regeneration of ileal mucosa onto the serosal surface of the cecum. The regeneration of ileal mucosa can then be evaluated at different times. The wound model also allows us to determine the rate of intestinal regeneration for a known size of intestinal wound and can be compared in different situations (e.g. with and without EGF and Peyer’s patches).At the light microscopic level it appeared that epithelial cells involved in regeneration of ileal mucosa originated from the enlarged crypts adjacent to the intestinal wound and migrated in an orderly fashion onto the serosal surface of the cecum. The migrating epithelial cells later formed crypts and villi by the process of invagination and evagination respectively. There were also signs of proliferation of smooth muscles underneath the migratory epithelial cells.

Mechanisms of active Cl- secretion by frog gastric mucosa

1987 ◽  
Vol 252 (4) ◽  
pp. G543-G547 ◽  
Author(s):  
W. W. Reenstra ◽  
J. D. Bettencourt ◽  
J. G. Forte
Keyword(s):  
Gastric Mucosa ◽  
Acid Secretion ◽  
Cation Exchange ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Potential Difference ◽  
Cl Secretion ◽  
Oxyntic Cell

Net Cl- flux across the bullfrog gastric mucosa was examined to test the hypothesis that Cl-secretion (JClnet) can be driven by either of the two cation exchange pumps in the oxyntic cell. The effects on JClnet of ouabain, an Na+-K+ pump inhibitor, and omeprazole, an H+-K+ pump inhibitor were examined. Omeprazole abolished acid secretion (JH) and reduced JClnet in bullfrog gastric mucosa. For mucosae at open circuit the omeprazole-induced decrease in JH was not significantly different than the decrease in JClnet, and the transmucosal potential difference (PD) was increased. When short-circuited mucosae were treated with omeprazole, the decrease in JClnet was significantly less than the decrease in JH, and short-circuit current (SCC) was correspondingly increased. After treatment of short-circuited mucosae with ouabain, the omeprazole-induced decreases in JH and JClnet were not significantly different, and no change in SCC occurred. For open-circuited mucosae, pretreatment with ouabain resulted in a significantly smaller omeprazole-induced increase in the transmucosal PD than was seen without ouabain pretreatment. Our data 1) show that both the H+-K+ pump and the Na+-K+ pump can drive Cl- secretion and 2) suggest that inhibition of the H+-K+ pump with omeprazole stimulates the Na+-K+ pump.

Ouabain binding to isolated frog gastric mucosa

1981 ◽  
Vol 241 (2) ◽  
pp. G104-G108
Author(s):  
V. M. France ◽  
R. P. Durbin
Keyword(s):  
Gastric Mucosa ◽  
Acid Secretion ◽  
Enzyme System ◽  
Specific Binding ◽  
Bathing Solution ◽  
Apical Surface ◽  
Ouabain Binding ◽  
High K ◽  
Wet Weight

Inhibition of gastric acid secretion by the cardiac glycoside, ouabain, is considerably reduced by elevating external K+ as first shown by Davenport (Proc. Soc. Exp. Biol. Med. 110: 613-615, 1962). To determine the possible role of K+ in this effect, we measured [3H]ouabain binding in isolated bullfrog gastric mucosa. Uptake of the labeled drug showed two components: one that saturated at 0.36 pmol ouabain per milligram wet weight and one that was linear with the external ouabain concentration. The former component is considered to represent specific binding to Na+-K+-ATPase; activity of this enzyme system in mucosal homogenates was 0.2 mumol per milligram protein per hour. Increase of K+ in the nutrient bathing solution from 3 to 30 mM, or replacement of Na+ by K+ in the secretory bathing solution, largely reversed inhibition of acid secretion by ouabain but did not affect maximum specific binding. The results fit a model in which Na+-K+-ATPase is normally required in oxyntic cells to maintain a high K+ level, which in turn supports exchange of K+ for H+ at the apical surface.

scholarly journals Visualization of binding sites for bovine parathyroid hormone (PTH 1-84) on cultured kidney cells with a biotinyl-b-PTH (1-84) antagonist.

1986 ◽  
Vol 34 (3) ◽  
pp. 357-361 ◽  
Author(s):  
A Niendorf ◽  
M Dietel ◽  
H Arps ◽  
J Lloyd ◽  
G V Childs
Keyword(s):  
Parathyroid Hormone ◽  
Binding Sites ◽  
Monolayer Culture ◽  
Cultured Cells ◽  
Microscopic Level ◽  
Kidney Cells ◽  
Light Microscopic Level ◽  
Cortical Cells ◽  
Fold Excess ◽  
Bovine Parathyroid Hormone

Parathyroid hormone (PTH) receptors have been found in a subpopulation of kidney cells. In this report, we investigated the feasibility of techniques that apply a partial antagonist of PTH conjugated to biotin to localize receptors cytochemically on bovine kidney cortical cells in monolayer culture at the light microscopic level. Biotinylated bovine PTH (1-84) (biotinyl-PTH) was bound to the cultured cells for 1-30 min at 37 degrees C in the amounts of 10(-5) -10(-10) M. In a different set of experiments, the cells were also exposed to a solution containing 10(-6) M biotinylated PTH and an excess of unlabeled PTH, insulin, adrenocorticotropin, or calcitonin for 10 and 30 min at 37 degrees C to test the specificity of the binding. The cells were then fixed in 2.5% glutaraldehyde and stained with the avidin-biotin peroxidase complex (ABC) technique. Diffuse labeling was evident on 30% of the cells in 10 min with concentrations of biotinyl-PTH as low as 10(-8) M. The stain was diffuse, but more intense after 1-10 min in higher concentrations (10(-6) M). If a 15-1500-fold excess of unlabeled PTH was added to the biotinyl-PTH, no staining was observed. The other peptides (insulin, ACTH or calcitonin) had no effect on binding. Longer times in biotinyl-PTH (10(-6) M for 10-30 min) resulted in intense patches of label on the cells resembling caps (in addition to the pale diffuse label). The percentage of labeled cells in the monolayer (30%) did not change with time. These studies show that a partial antagonist of PTH can be used as a cytochemical probe for specific PTH receptors in a subpopulation of cultured cortical kidney cells.

Ultrastructural Investigation of Spontaneous Pituitary Adenomas in Aging Sprague-Dawley Rats

1982 ◽  
Vol 40 ◽  
pp. 216-217
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Microscopic Study ◽  
Pituitary Adenomas ◽  
Wistar Rats ◽  
Microscopic Level ◽  
Sprague Dawley ◽  
Prolactin Cells ◽  
Light Microscopic Level ◽  
Ultrastructural Investigation ◽  
Sprague Dawley Rats ◽  
Long Evans

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.

The Fine Structure of Irradiated Mouse Heart

1976 ◽  
Vol 34 ◽  
pp. 184-185
Author(s):  
Vivian V. Yang ◽  
S. Phyllis Stearner
Keyword(s):  
Microscopic Level ◽  
Ultrastructural Changes ◽  
Mouse Heart ◽  
Blood Vessel Wall ◽  
Histopathological Changes ◽  
Light Microscopic Level ◽  
Γ Rays ◽  
Fission Neutrons ◽  
Total Body

The heart is generally considered a radioresistant organ, and has received relatively little study after total-body irradiation with doses below the acutely lethal range. Some late damage in the irradiated heart has been described at the light microscopic level. However, since the dimensions of many important structures of the blood vessel wall are submicroscopic, investigators have turned to the electron microscope for adequate visualization of histopathological changes. Our studies are designed to evaluate ultrastructural changes in the mouse heart, particularly in the capillaries and muscle fibers, for 18 months after total-body exposure, and to compare the effects of 240 rad fission neutrons and 788 rad 60Co γ-rays.Three animals from each irradiated group and three control mice were sacrificed by ether inhalation at 4 days, and at 1, 3, 6, 12, and 18 months after irradiation. The thorax was opened and the heart was fixed briefly in situwith Karnofsky's fixative.

Liquid crystalline ordering of paired helical filaments in neurofibrillary tangles of Alzheimer's disease

1986 ◽  
Vol 44 ◽  
pp. 348-349
Author(s):  
D.F. Clapin ◽  
V.J.A. Montpetit
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurofibrillary Tangles ◽  
Liquid Crystalline ◽  
Amyloid Fibrils ◽  
Geometric Analysis ◽  
Paired Helical Filaments ◽  
Microscopic Level ◽  
Light Microscopic Level ◽  
Regular Spacing

Alzheimer's disease is characterized by the accumulation of abnormal filamentous proteins. The most important of these are amyloid fibrils and paired helical filaments (PHF). PHF are located intraneuronally forming bundles called neurofibrillary tangles. The designation of these structures as "tangles" is appropriate at the light microscopic level. However, localized domains within individual tangles appear to demonstrate a regular spacing which may indicate a liquid crystalline phase. The purpose of this paper is to present a statistical geometric analysis of PHF packing.

Ultrastorcture of Cerebellar Purkinje Cells in Rats Subjected To Partial Global Cerebral Ischemia

1985 ◽  
Vol 43 ◽  
pp. 674-675
Author(s):  
R.V.W. Dimlich ◽  
M.H. Biros
Keyword(s):  
Cerebral Ischemia ◽  
Purkinje Cells ◽  
Cell Types ◽  
Microscopic Level ◽  
Global Cerebral Ischemia ◽  
Light Microscopic Level ◽  
Cerebellar Damage ◽  
Cerebellar Injury ◽  
Cerebellar Purkinje Cells ◽  
Cell Changes

In severe cerebral ischemia, Purkinje cells of the cerebellum are one of the cell types most vulnerable to anoxic damage. In the partial (forebrain) global ischemic (PGI) model of the rat, Paljärvi noted at the light microscopic level that cerebellar damage is inconsistant and when present, milder than in the telencephalon, diencephalon and rostral brain stem. Cerebellar injury was observed in 3 of 4 PGI rats following 5 minutes of reperfusion but in none of the rats after 90 min of reperfusion. To evaluate a time between these two extremes (5 and 90 min), the present investigation used the PGI model to study the effects of ischemia on the ultrastructure of cerebellar Purkinje cells in rats that were sacrificed after 30 min of reperfusion. This time also was chosen because lactic acid that is thought to contribute to ischemic cell changes in PGI is at a maximum after 30 min of reperfusion.

An ultrastructural study on the shark liver

1990 ◽  
Vol 48 (3) ◽  
pp. 512-513
Author(s):  
Masako Yamada ◽  
Yutaka Tanuma
Keyword(s):  
Portal Vein ◽  
Kupffer Cells ◽  
Ultrastructural Study ◽  
Lipid Droplets ◽  
Microscopic Level ◽  
The Other ◽  
Fish Stock ◽  
Structural Studies ◽  
Light Microscopic Level ◽  
Perfusion Fixation

Although many fine structural studies on the vertebrate liver have been reported on mammals, avians, reptiles, amphibians, teleosts and cyclostomes, there are no studies on elasmobranchii liver except one by T. Ito etal. (1962) who studied it on light microscopic level. The purpose of the present study was to as certain the ultrastructural details and cytochemical characteristics of normal elasmobranchii liver and was to compare with the other higher vertebrate ones.Seventeen Scyliorhinus torazame, one kind of elasmobranchii, were obtained from the fish stock of the Ueno Zoo aquarium, Ueno, Tokyo. The sharks weighing about 300-600g were anesthetized with MS-222 (Sigma), and the livers were fixed by perfusion fixation via the portal vein according to the procedure of Y. Saito et al. (1980) for 10 min. Then the liver tissues were immersed in the same fixative for 2 hours and postfixed with 1% OsO4-solution in 0.1 Mc acodylate buffer for one hour. In order to make sure a phagocytic activity of Kupffer cells, latex particles (0.8 μm in diameter, 0.05mg/100 g b.w.) were injected through the portal vein for one min before fixation. For preservation of lipid droplets in the cytoplasm, a series of these procedure were performed under ice cold temperature until the end of dehydration.

Expression of NKCC1 and NKCC2 in gastric mucosa and their possible role in acid secretion

2010 ◽  
Vol 34 (8) ◽  
pp. S2-S2
Author(s):  
Tuo Ji ◽  
Hong Xue ◽  
Zhangfeng Dou ◽  
Yue Zhang ◽  
Jinxia Zhu
Keyword(s):  
Gastric Mucosa ◽  
Acid Secretion
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