Search Results
Results 501 - 550 of 1831
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Hug M J - - 2001
We have previously demonstrated that the airway serous cell line Calu-3 employs a number of pH regulatory mechanisms required for bicarbonate secretion by these cells. The aim of the present study was to investigate the pH regulatory mechanisms of serous cells of freshly isolated submucosal glands (SMG). Porcine SMG were ...
Lin L Y - - 2001
Similar to those of the gills of adults, three types of mitochondria-rich (MR) cells with different morphologies of apical surfaces (wavy convex, shallow basin, and deep hole) were identified on the integument of freshwater-acclimated tilapia larvae (Oreochromis mossambicus). The object of this study is to test the hypothesis that these ...
Zydlewski J - - 2001
Location, abundance, and morphology of gill chloride cells were quantified during changes in osmoregulatory physiology accompanying early development in American shad, Alosa sapidissima. During the larval-juvenile transition of shad, gill chloride cells increased 3.5-fold in abundance coincident with gill formation, increased seawater tolerance, and increased Na(+),K(+)-ATPase activity. Chloride cells were ...
Hartl M G.J. - - 2001
The effects of exposure to sediment-associated tri-n-butyltin chloride (TBT) and triphenyltin chloride (TPhT) were examined in the euryhaline European flounder, Platichthys flesus (L.). The effects were quantified by measuring the changes in sodium efflux, Na(+)/K(+)-ATPase activity and the numbers, areas and distribution of chloride cells in the gills of freshwater-adapted ...
Bush P G - - 2001
Articular chondrocytes in vivo are exposed to a changing osmotic environment under both physiological (static load) and pathological (osteoarthritis) conditions. Such changes to matrix hydration could alter cell volume in situ and influence matrix metabolism. However the ability of chondrocytes to regulate their volume in the face of osmotic perturbations ...
Tanaka J Y - - 2001
Biphasic transport of water and dimethyl sulfoxide (Me(2)SO), a common cryoprotective agent (CPA), in algal cells was induced and measured on a cryoperfusion stage. A two-step experimental protocol provided data for the volumetric response of Chlorococcum (C.) texanum to impermeable and permeable solutes. First, the cells were exposed to a ...
Payne J A - - 2001
A low K-resistant mutant Madin-Darby canine kidney (MDCK) cell line, LK-C1, has been shown previously to lack functional Na-K-Cl cotransporter (NKCC) activity, indicating that it may be a useful NKCC "knockout" cell line for structure-function studies. Using immunological probes, we first characterized the defect in the endogenous NKCC protein of ...
Aschner M - - 2001
We tested the hypothesis that astrocytes swell in response to ethanol (EtOH) exposure. The experimental approach consisted of an electrical impedance method designed to measure cell volume. In chronic experiments, EtOH (100 mM) was added to the culture media for 1, 3, or 7 days. The cells were subsequently exposed ...
Lochmann H - - 2001
A new capillary electrophoresis system with direct UV detection for the analysis of the tobacco alkaloids nicotine, nornicotine and anabasine in plant microsamples was developed. An electrolyte containing a high concentration of citric acid to provide good buffer capacity at pH 3.6 was found to be most suitable in terms ...
Mooren F C - - 2001
1. A new method was developed for non-invasive investigations of intracellular pH (pHi) regulation in different cell types of the isolated perfused pancreas using a confocal laser scanning technique. 2. After removal of the rat pancreas the coeliac artery was cannulated and the splenic segment of the pancreas was perfused ...
Karumanchi S A - - 2001
Mutations in the von Hippel-Lindau (VHL) tumor suppressor gene are thought to play a critical role in the pathogenesis of both sporadic and VHL disease-associated clear-cell renal carcinomas (RCC). Differential display-PCR identified the AE2 anion exchanger as a candidate VHL target gene. AE2 mRNA and polypeptide levels were approximately threefold ...
Bowles D W. - - 2001
To assess cation-chloride cotransporter activity in Sf9 cells, cation chromatography was used to measure initial uptake rates of Rb. Rb exchanged with cellular K, with 30% of cellular K replaced after a 40 min exposure to Rb. Rb uptake into Sf9 cells was not inhibited by 50 µmol l(-1) ouabain. ...
Schwartz G J - - 2001
The cortical collecting duct (CCD) is capable of secreting H(+) or HCO3(-) depending on the acid-base status in vivo. Transport is a function of two types of intercalated cells in the CCD: A-intercalated cells secrete H(+) and B-intercalated cells secrete HCO3(-). Metabolic acidosis results in a decrease in HCO3(-) secretion ...
Redondo J - - 2001
BACKGROUND: Hypothermia-induced changes in cell volume and ionic transport systems of coronary endothelial cells may play a role in the development of coronary artery disease in cardiac transplant recipients. METHODS: Coronary endothelial cells were incubated in University of Wisconsin solution or culture control medium for up to 48 hours at ...
Urcelay E - - 2001
We have recently reported that lymphoblasts from late onset Alzheimer's disease (AD) patients show distinct intracellular pH homeostatic features than those obtained from age-matched healthy donors. Here we report that another distinct feature of AD lymphoblasts is their increased rate of proliferation in serum containing medium, suggesting a different responsiveness ...
Doroshenko P - - 2001
Cell cycle-related changes in the ability to regulate cell volume following hyposmotic swelling were studied in mouse fibroblasts using videomicroscopy and the whole-cell patch clamp technique. Regulatory volume decrease (RVD) and volume-sensitive Cl- conductance (G(Cl,vol)) were measured: (1) in proliferating cells of different sizes; (2) in cells arrested in defined ...
Chao M - - 2001
The test sensitivities and reproducibilities based on different response endpoints (cell density and total cell volume) were compared using both bath and continuous algal toxicity tests. Parameters related to algal cell density are found to be more sensitive and reproducible than total cell volume which bears a direct correlation to ...
Haddad J J - - 2001
Electrophoretic mobility shift assays revealed minimal levels of NF-kappaB activity in rat distal lung epithelial cells cultured at fetal (23 mmHg) or adult alveolar (100 mmHg) P(O2), but revealed significant activation of this transcription factor in cells exposed to a rise in P(O2) mimicking that experienced at birth. This response ...
Roman R M - - 2001
Membrane Cl(-) channels play an important role in cell volume homeostasis and regulation of volume-sensitive cell transport and metabolism. Heterologous expression of ClC-2 channel cDNA leads to the appearance of swelling-activated Cl(-) currents, consistent with a role in cell volume regulation. Since channel properties in heterologous models are potentially modified ...
Matthews J B - - 2001
The response of three human monocytic cell lines (Monomac-1, U937 and THP-1) to challenge with polyethylene particles of known size and dose was evaluated. Particles with a mean size of 0.21, 0.49, 4.3, 7.2, and 88 microm were co-cultured with the cells for 24 hours prior to the assessment of ...
Shen M R - - 2001
The aim of this study was to investigate swelling-activated taurine and K+ transport in human cervical cancer cells under various culture conditions, testing the hypothesis that the progression of cell cycle was accompanied by differential activities of swelling-activated transport pathways. Aphidicolin, an inhibitor of deoxyribonucleic acid (DNA) synthesis, was used ...
Stapleton F - - 2001
BACKGROUND/AIMS: Current contact lenses (CLs) when worn on an extended wear basis cause corneal epithelial alterations. The aim of this study was to evaluate changes in corneal epithelial cell morphology and physiology following short term (3 months) wear of highly oxygen permeable CLs and to compare this with disposable CLs. ...
Scheiner-Bobis G - - 2001
Sanguinarine, an alkaloid from Sanguinaria canadensis, has no effect on the yeast Saccharomyces cerevisiae at concentrations of up to 225 microM. Yeast cells become sensitive to sanguinarine and lose cytosolic K+ in a time- and concentration-dependent manner when they express the mammalian Na+,K+-ATPase (sodium pump). Dose-response studies show that sanguinarine ...
De Petris L - - 2001
Onset and correction of hypernatraemia constitute major hypertonic stresses for mammalian cells. Cells respond by activating specific osmoregulatory mechanisms allowing to preserve their volume and to adapt to their new environmental conditions. These processes have major implications in the management of hypernatraemia. In particular, cells chronically exposed to hypertonic conditions ...
Rajasekaran S A - - 2001
The cell adhesion molecule E-cadherin has been implicated in maintaining the polarized phenotype of epithelial cells and suppression of invasiveness and motility of carcinoma cells. Na,K-ATPase, consisting of an alpha- and beta-subunit, maintains the sodium gradient across the plasma membrane. A functional relationship between E-cadherin and Na,K-ATPase has not previously ...
Luciani A M - - 2001
Cell volumes decreased in HeLa cells as a function of time after seeding during exponential growth. Cell volume distributions revealed the presence of two cell populations in all stages of growth. When cells approached confluence, the ratio of the two populations abruptly shifted towards that characterised by the smallest volume. ...
Yamamoto S - - 2001
The effects of the activation of cyclic AMP-dependent Cl- current (ICl,cAMP) on cell volume were studied at various [K+]o under isosmotic conditions in guinea-pig ventricular myocytes. The area of the cell image obtained with videomicroscopy was used as an index of cell volume. I(Cl,cAMP) was activated by adrenaline (5.5 microM). ...
Melloul M - - 2001
The aim of this study was to assess the correlation between technetium-99m methoxyisobutylisonitrile (MIBI) uptake by parathyroid adenomas, oxyphil cell content and volume of the lesions. Thirty-one patients with parathyroid adenomas were evaluated prospectively. Preoperative double-phase 99mTc-MIBI scintigraphy was performed in all patients and tracer uptake by parathyroid lesions was ...
Dermott J M - - 2001
Heterotrimeric G protein G12 stimulates diverse physiological responses including the activities of Na+/H+ exchangers and Jun kinases. We have observed that the expression of the constitutively activated, GTPase-deficient mutant of Galpha(12) (Galpha(12)QL) accelerates the hyperosmotic response of NIH3T3 cells as monitored by the hyperosmotic stress-stimulated activity of JNK1. The accelerated ...
Thinnes F P - - 2001
There is indirect evidence that the plasmalemma-integrated eukaryotic porin (the voltage-dependent anion-selective channel, VDAC) functions as the outwardly rectifying chloride channel (ORCC). The channel, which is believed to play a role in cell volume regulation, appears to be relevant for cystic fibrosis (CF) therapy, in that it may function as ...
Barros L F - - 2001
Necrosis, as opposed to apoptosis, is recognized as a nonspecific cell death that induces tissue inflammation and is preceded by cell edema. In non-neuronal cells, the latter has been explained by defective outward pumping of Na(+) caused by metabolic depletion or by increased Na(+) influx via membrane transporters. Here we ...
Chang I C - - 2001
The objective of this study is to test the hypothesis that morphologically different mitochondria-rich (MR) cells may be responsible for the uptake of different ions in freshwater-adapted fish. Tilapia (Oreochromis mossambicus) were acclimated to high-Ca, mid-Ca, low-Ca, and low-NaCl artificial freshwater, respectively, for 2 wk. Cell densities of wavy-convex, shallow-basin, ...
Allansson L - - 2001
Acute exposure to 100 mM isotonic ethanol (EtOH) increased intracellular Ca2+ concentration ([Ca2+]i), induced cell swelling, and transformed actin cytoskeleton in astroglial primary cultures from rat cerebral cortex. Fluorometric recordings of fluo-3AM- or fura-2AM-incubated astroglial cells revealed that EtOH induced [Ca2+]i transients in a small population of the cells. Cell ...
Lauf P K - - 2001
Coupled K and Cl movements are mediated by several isoforms of the K-Cl cotransporter (COT) encoded by the KCC genes. The ubiquitous KCC1 isoform, important for cell volume and ion homeostasis, has 12 transmembrane domains (Tmds), and cytoplasmic N- and C-terminal domains (Ntd and Ctd). This study investigates the cellular ...
Wong C K - - 2001
The purpose of the present study was to determine the effects of cortisol on the development of the freshwater chloride cell (CC), using flow cytometry. Scanning electron microscopy was used to determine the corresponding modifications in CC apical structure. Simultaneously, biochemical analyses were conducted to determine the activities of transport ...
Dahl J P - - 2000
We have examined the relationship between Na,K-ATPase and FGF-2 secretion in transfected primate cells. FGF-2 lacks a classic hydrophobic export signal, and the mechanisms mediating its secretion are unknown. To monitor secretion, a FLAG epitope tag was inserted into the carboxyl terminus of the 18 kDa form of human FGF-2, ...
Laroche-Joubert N - - 2000
Rat collecting ducts exhibit type I or type III K(+)-ATPase activities when animals are fed a normal (NK) or a K(+)-depleted diet (LK). This study aimed at determining functionally the cell origin of these two K(+)-ATPases. For this purpose, we searched for an effect on K(+)-ATPases of hormones that trigger ...
Wang C Z - - 2000
The Na(+)-driven Cl(-)/HCO(3)(-) exchanger is an important regulator of intracellular pH in various cells, but its molecular basis has not been determined. We show here the primary structure, tissue distribution, and functional characterization of Na(+)-driven chloride/bicarbonate exchanger (designated NCBE) cloned from the insulin-secreting cell line MIN6 cDNA library. The NCBE ...
Dang Z C - - 2000
Effects of waterborne Cu (2.4 microM) on the expression of glucocorticoid receptor (GR) and metallothionein (MT) in the branchial epithelium of freshwater rainbow trout (Oncorhynchus mykiss) was studied by immunocytochemistry. After 5 days of Cu exposure, the number of GR-immunoreactive (GR-ir) cells in the gill epithelium had decreased, whereas the ...
Ostberg B C - - 2000
To study the secretion from endocrine cells in culture, we have developed a cell column perfusion system with a time resolution of 4 s. The core of the system is a perfusion chamber with a cell-supporting matrix of monosized polystyrene beads. The particles are solid and can withstand a high ...
Galtung H K - - 2000
RATIONALE AND OBJECTIVES: Most radiographic contrast media (CM) are hyperosmotic and pose an osmotic threat to cells they are in contact with. To study these effects at the cellular level, cell volume regulatory mechanisms were observed in proximal renal tubules following exposure to the CM iohexol, ioxaglate, and iodixanol. MATERIALS ...
Mori R - - 2000
A new quantitative method was devised both to establish an objective standard for morphometric diagnosis and to determine the extent of degeneration in osteoarthritic cartilage. Eight normal and forty-eight osteoarthritic humeral heads, subsequently confirmed by light microscopy, were obtained at necropsy. The articular cartilage was observed in situ with a ...
Rouzaire-Dubois B - - 2000
K+ and Cl- channels are involved in regulating the proliferation of a number of cell types. Two main hypotheses have been proposed to explain the mechanism by which these channels influence cell proliferation: regulation of membrane potential and regulation of cell volume. In order to test these hypotheses, we measured, ...
Ho C K - - 2000
Ouabain is a specific inhibitor of sodium, potassium-dependent adenosine triphosphatase (Na,K-ATPase), a P-type ion-transporting ATPase which is essential for the maintenance of adequate concentrations of intracellular Na+ and K+ ions. The present study describes the establishment of a ouabain-resistant mutant, TLouaR, from a human trophoblast cell line TL. Morphologically TL ...
Loffing J - - 2000
Serous cells secrete Cl(-) and HCO(3)(-) and play an important role in airway function. Recent studies suggest that a Cl(-)/HCO(3)(-) anion exchanger (AE) may contribute to Cl(-) secretion by airway epithelial cells. However, the molecular identity, the cellular location, and the contribution of AEs to Cl(-) secretion in serous epithelial ...
Lagana A - - 2000
The Na(+)/H(+) exchanger NHE1 is involved in intracellular pH homeostasis and cell volume regulation and accumulates with actin in the lamellipodia of fibroblasts. In order to determine the role of NHE1 following epithelial transformation and the acquisition of motile and invasive properties, we studied NHE1 expression in polarized MDCK cells, ...
Duyckaerts C - - 2000
The conditions of regularity and isotropy, required by standard morphometric procedures, are generally not fulfilled in the central nervous system (CNS) where cells are distributed in a highly complex manner. The evaluation of the mean numerical density of neuronal or glial cells does not take into account the topographical heterogeneity ...
Ramirez M A - - 2000
Cell pH regulation was investigated in the T84 cell line derived from epithelial colon cancer. Cell pH was measured by ratiometric fluorescence microscopy using the fluorescent probe BCECF. Basal pH was 7.17 +/- 0.023 (n = 48) in HEPES Ringer. After acidification by an ammonium pulse, cell pH recovered toward ...
Zwingmann C - - 2000
NH(4)Cl (10 mM) caused a sustained increase in the cell volume in immobilized, perfused F98 glioma cells to approx. 125% of control after 3 h, as measured by diffusion-weighted (1)H NMR spectroscopy. Concomitantly, the glutamine (Gln) concentration increased by 130%, accompanied by a marked decrease in cytosolic osmolytes, i.e. myo-inositol ...
Cauvi D - - 2000
Cell volume regulation by thyrotropin (TSH) and iodide, the main effectors involved in thyroid function, was studied in cultured thyroid cells. The mean cell volume, determined by performing 3-D reconstitution on confocal microscopy optical slices from living octadecylrhodamine-labeled cells cultured with both TSH and iodide (control cells), was 3.73 +/- ...
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