scholarly journals Teleost chloride cell. I. Response of pupfish Cyprinodon variegatus gill Na,K-ATPase and chloride cell fine structure to various high salinity environments.

1976 ◽  
Vol 70 (1) ◽  
pp. 144-156 ◽  
Author(s):  
K J Karnaky ◽  
S A Ernst ◽  
C W Philpott
Keyword(s):  
Cell Surface ◽  
Atpase Activity ◽  
High Salinity ◽  
Cell Structure ◽  
Chloride Cell ◽  
Salt Transport ◽  
Chloride Cells ◽  
Osmotic Gradient ◽  
Cyprinodon Variegatus ◽  
Very High

Certain euryhaline teleosts can tolerate media of very high salinity, i.e. greater than that of seawater itself. The osmotic gradient across the integument of these fish is very high and the key to their survival appears to be the enhanced ability of the gill to excrete excess NaCl. These fish provide an opportunity to study morphological and biochemical aspects of transepithelial salt secretion under conditions of vastly different transport rates. Since the cellular site of gill salt excretion is believed to be the "chloride cell" of the branchial epithelium and since the enzyme Na,K-ATPase has been implicated in salt transport in this and other secretory tissues, we have focused our attention on the differences in chloride cell structure and gill ATPase activity in the variegated pupfish Cyprinodon variegatus adapted to half-strength seawater (50% SW), seawater (100% SW), or double-stregth seawater (200% SW). The Na,K-ATPase activity in gill homogenates was 1.6 times greater in 100% SW. When 50% SW gills were compared to 100% SW gills, differences in chloride cell morphology were minimal. However, chloride cells from 200% SW displayed a marked hypertrophy and a striking increase in basal-lateral cell surface area. These results suggest that there are correlations among higher levels of osmotic stress, basal-lateral extensions of the cell surface, and the activity of the enzyme Na,K-ATPase.

Angiotensin II receptors in the gill of sea water- and freshwater-adapted eel

1997 ◽  
Vol 18 (1) ◽  
pp. 67-76 ◽  
Author(s):  
S Marsigliante ◽  
A Muscella ◽  
G P Vinson ◽  
C Storelli
Keyword(s):  
Image Analysis ◽  
Angiotensin Ii ◽  
Atpase Activity ◽  
Sea Water ◽  
Anguilla Anguilla ◽  
Chloride Cell ◽  
Chloride Cells ◽  
Angiotensin Ii Receptors ◽  
Receptor Subtypes ◽  
Ang Ii

ABSTRACT Immunocytochemistry of paraffin-embedded and cryostat sections of eel (Anguilla anguilla) gill showed that angiotensin II receptors (Ang II-R) were present in chloride cells, uniformly distributed in the cytoplasm and on surface membranes. Computerised image analysis of these preparations showed that gills from sea water (SW)-adapted animals had a significantly (3-fold) higher Ang II-R concentration compared with freshwater (FW)-adapted eel gills. Isoelectric focusing gel electrophoresis revealed two Ang II-R isoforms with pI 6·5 and 6·6 that were differentially modulated by environmental salinity: they were equally abundant in SW while in FW the pI 6·6/pI 6·5 ratio was 1·66. Using catalytic cytochemistry with image analysis, gill chloride cell membrane Na+/K+ATPase activity was shown to increase 4-fold in response to SW adaptation. Additionally, perfusion of gills for 30 min with 0·1, 10 or with 100 nM Ang II provoked a dose-dependent increment in Na+/K+ATPase activity in FW, and a biphasic response in SW gills in which activity was significantly increased at low Ang II concentrations but was reduced to basal values at 100 nM. The data suggest that adaptation to sea water significantly increases Ang II-R concentration in the chloride cell and, together with the effects of Ang II on Na+/K+ATPase activity, suggest a role for this hormone in gill NaCl retention. The different responses of Na+/K+ATPase to Ang II stimulation in FW and SW may be attributed to the presence of two receptor subtypes that are differently modulated by salinity and that have opposing effects on Na+/K+ATPase.

Evidence for a mineralocorticoid-like receptor linked to branchial chloride cell proliferation in freshwater rainbow trout

2001 ◽  
Vol 204 (22) ◽  
pp. 3953-3961 ◽  
Author(s):  
Katherine A. Sloman ◽  
Patrick R. Desforges ◽  
Kathleen M. Gilmour
Keyword(s):  
Cell Proliferation ◽  
Rainbow Trout ◽  
Atpase Activity ◽  
Coconut Oil ◽  
Chloride Cell ◽  
Chloride Cells ◽  
Corticosteroid Receptor ◽  
Potent Antagonist ◽  
Mineralocorticoid Hormone

SUMMARY Fish acclimated to ion-deficient water exhibit proliferation of branchial chloride cells. The objective of the present study was to investigate the role of cortisol in this response using the corticosteroid receptor antagonists RU486 and spironolactone. RU486 is a potent antagonist of the glucocorticoid actions of cortisol, whereas spironolactone exhibits high-affinity binding to mineralocorticoid receptors, with a resulting blockade of mineralocorticoid properties in mammals. Untreated rainbow trout, as well as rainbow trout given a single intraperitoneal implant of coconut oil alone, coconut oil containing RU486 (0.5 mg g–1) or coconut oil containing spironolactone (0.1 mg g–1), were exposed to either dechlorinated city-of-Ottawa tapwater or artificial softwater for 7 days. Neither corticosteroid antagonist nor acclimation condition affected circulating plasma cortisol levels, plasma ion concentrations or gill Na+-K+-ATPase activity. Kidney Na+-K+-ATPase activity was significantly higher in softwater-acclimated fish than in fish held in dechlorinated tapwater. In addition, whereas RU486 treatment was found to be without effect on gill morphometrics, treatment with spironolactone inhibited the proliferation of chloride cells normally associated with acclimation to ion-deficient water. The results of the present study provide further evidence for the mineralocorticoid actions of cortisol in freshwater fish, specifically in eliciting chloride cell proliferation. Furthermore, these results support the hypothesis that distinct glucocorticoid and mineralocorticoid receptor populations are present in teleost fish, despite the apparent absence of the classic mineralocorticoid hormone, aldosterone.

scholarly journals The effect of salinity on osmoregulation and development of the juvenile fat snook, Centropomus parallelus (POEY)

2013 ◽  
Vol 73 (3) ◽  
pp. 609-615 ◽  
Author(s):  
FC. Sterzelecki ◽  
E. Rodrigues ◽  
E. Fanta ◽  
CAO. Ribeiro
Keyword(s):  
Atpase Activity ◽  
Salt Water ◽  
Cell Ultrastructure ◽  
Chloride Cell ◽  
Chloride Cells ◽  
Secretory Cells ◽  
Salinity Change ◽  
Short Term ◽  
Short Term Exposure

Eurihaline fish support waters with different salt concentration. However, numerous studies have shown that salinity can affect fish development. Thus, the effect of salinity change from 20 to 5 and 35 on survival, weight, length, gill chloride cell ultrastructure and gill Na+, K+ ATPase activity was evaluated in Centropomus parallelus following short-term (6, 24 and 96 hours) and long-term exposure (30 and 60 days). Salinity did not affect C. parallelus survival, final weight and length. The quantity of chloride cells increased visibly at salinities of 5 and 35, with the cells exhibiting the typical features of uptake and secretory cells, respectively. Na+, K+ ATPase activity in the gill of the C. parallelus was significantly greater at a salinity of 5 than at a salinity of 20 or 35 after 96 hours, but not after 30 or 60 days. These results indicate that salinity change from high to low salt water induces gill chloride cell and Na+, K+ ATPase activity adaptations after short-term exposure. However, after long-term exposure at salinity 5, gill Na+, K+ ATPase activity is no more necessary at high levels. The increase in salinity to 35 does not induce significant change in gills. Juveniles of C. parallelus may thus be capable of acclimating to salinities of 5 to 35 for 60 days without significant effects on development.

Mosaic structure in the plasma membrane: spiral arrays of subunits in the cytoplasmic tubules of lamprey chloride cells

1982 ◽  
Vol 56 (1) ◽  
pp. 441-452
Author(s):  
T. Hatae ◽  
E.L. Benedetti
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
High Salinity ◽  
Petromyzon Marinus ◽  
Freeze Fracture ◽  
Chloride Cell ◽  
Chloride Cells ◽  
Ionic Homeostasis ◽  
Electron Dense Material ◽  
Basolateral Plasma Membrane

The membrane architecture of the cytoplasmic tubules in lamprey chloride cells has been studied by electron microscopy using thin-section and freeze-fracture techniques. The chloride cell of lampreys (Lampetra japonica, Petromyzon marinus) is largely occupied with a continuous network of cytoplasmic tubules, which are derived from the invagination of the basolateral plasma membrane. The lumenal surface of this tubular network is covered with spirally wound parallel rows of electron-dense material, which consist of linear aggregates of particles. Freeze-fracture of the membrane of the tubules also shows spiral arrangements of particles (approximately 9 nm in diameter) on the P-face and complementary shallow grooves on the E-face. These arrangements of particles are about 17 nm apart and wound at a pitch of about 45 degrees. These complex organizations of the membrane of the tubules are probably the sites of transport of ion and water, which is essential for the maintenance of ionic homeostasis in both low- and high-salinity environments.

Influence of Photoperiod on the Number and Ultrastructure of Gill Chloride Cells of the Atlantic Salmon (Salmo salar) before and during Smoltification

1991 ◽  
Vol 48 (7) ◽  
pp. 1302-1307 ◽  
Author(s):  
Robert T. Lubin ◽  
A. W. Rourke ◽  
Richard L. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Atpase Activity ◽  
Salmo Salar ◽  
Chloride Cell ◽  
Constant Light ◽  
Chloride Cells ◽  
Cell Numbers ◽  
Atlantic Salmon Salmo Salar ◽  
Threefold Increase ◽  
Natural Photoperiod

Atlantic salmon (Salmo salar) larger than 9 cm held under constant light since October had greater numbers of gill chloride cells in February compared with fish held under simulated natural photoperiod. By April, fish raised under simulated natural photoperiod were able to survive salinity tests, had a threefold increase in Na+/K+ ATPase activity, and had increased chloride cell numbers. These increases and salinity tolerance did not occur in fish raised under constant light. Only fish reared under constant light developed apical pits with large and numerous microvilli.

SATELLITE DATA FOR INVESTIGATION OF RECENT STATE AND PROCESSES IN THE SIVASH BAY

2017 ◽  
Author(s):  
Ekaterina Shchurova ◽  
Ekaterina Shchurova ◽  
Rimma Stanichnaya ◽  
Rimma Stanichnaya ◽  
Sergey Stanichny ◽  
...  
Keyword(s):  
Satellite Data ◽  
Water Exchange ◽  
High Salinity ◽  
Meteorological Data ◽  
Sea Surface ◽  
Azov Sea ◽  
Seasonal Wind ◽  
Ice Regime ◽  
Very High

Sivash bay is the shallow-water lagoon of the Azov Sea. Restricted water exchange and high evaporation form Sivash as the basin with very high salinity. This factor leads to different from the Azov Sea thermal and ice regimes of Sivash. Maine aim of the study presented to investigate recent state and changes of the characteristics and processes in the basin using satellite data. Landsat scanners TM, ETM+, OLI, TIRS together with MODIS and AVHRR were used. Additionally NOMADS NOAA and MERRA meteorological data were analyzed. The next topics are discussed in the work: 1. Changes of the sea surface temperature, ice regime and relation with salinity. 2. Coastal line transformation – long term and seasonal, wind impact. 3. Manifestation of the Azov waters intrusions through the Arabat spit, preferable wind conditions.

scholarly journals Body mass-specific Na+-K+-ATPase activity in the medullary thick ascending limb: implications for species-dependent urine concentrating mechanisms

2018 ◽  
Vol 314 (4) ◽  
pp. R563-R573 ◽  
Author(s):  
Mun Aw ◽  
Tamara M. Armstrong ◽  
C. Michele Nawata ◽  
Sarah N. Bodine ◽  
Jeeeun J. Oh ◽  
...  
Keyword(s):  
Protein Expression ◽  
Atpase Activity ◽  
Metabolic Rate ◽  
Body Mass ◽  
Whole Body ◽  
Osmotic Gradient ◽  
Thick Ascending Limb ◽  
Rat Strains ◽  
Kangaroo Rat ◽  
Gene And Protein Expression

In general, the mammalian whole body mass-specific metabolic rate correlates positively with maximal urine concentration (Umax) irrespective of whether or not the species have adapted to arid or mesic habitat. Accordingly, we hypothesized that the thick ascending limb (TAL) of a rodent with markedly higher whole body mass-specific metabolism than rat exhibits a substantially higher TAL metabolic rate as estimated by Na+-K+-ATPase activity and Na+-K+-ATPase α1-gene and protein expression. The kangaroo rat inner stripe of the outer medulla exhibits significantly higher mean Na+-K+-ATPase activity (~70%) compared with two rat strains (Sprague-Dawley and Munich-Wistar), extending prior studies showing rat activity exceeds rabbit. Furthermore, higher expression of Na+-K+-ATPase α1-protein (~4- to 6-fold) and mRNA (~13-fold) and higher TAL mitochondrial volume density (~20%) occur in the kangaroo rat compared with both rat strains. Rat TAL Na+-K+-ATPase α1-protein expression is relatively unaffected by body hydration status or, shown previously, by dietary Na+, arguing against confounding effects from two unavoidably dissimilar diets: grain-based diet without water (kangaroo rat) or grain-based diet with water (rat). We conclude that higher TAL Na+-K+-ATPase activity contributes to relationships between whole body mass-specific metabolic rate and high Umax. More vigorous TAL Na+-K+-ATPase activity in kangaroo rat than rat may contribute to its steeper Na+ and urea axial concentration gradients, adding support to a revised model of the urine concentrating mechanism, which hypothesizes a leading role for vigorous active transport of NaCl, rather than countercurrent multiplication, in generating the outer medullary axial osmotic gradient.

scholarly journals Synthesis of plasmalemmal glycoproteins in intestinal epithelial cells. Separation of Golgi membranes from villus and crypt cell surface membranes; glycosyltransferase activity of surface membrane

1978 ◽  
Vol 77 (3) ◽  
pp. 722-734 ◽  
Author(s):  
MM Weiser ◽  
MM Neumeier ◽  
A Quaroni ◽  
K Kirsch
Keyword(s):  
Cell Surface ◽  
Atpase Activity ◽  
Surface Membrane ◽  
Basal Membrane ◽  
Crypt Cell ◽  
Velocity Sedimentation ◽  
Intact Cells ◽  
Microvillus Membrane ◽  
Villus Cell ◽  
Crypt Cells

The relationship between Golgi and cell surface membranes of intestinal cells was studied. These membranes were isolated from intestinal crypt cells and villus cells. The villus cell membranes consisted of microvillus membrane, a Golgi-rich fraction, and two membrane fractions interpreted as representing lateral-basal membranes. The villus cell microvillus membrane was purified by previously published techniques while the other membranes were obtained from isolated cells by differential centrifugation and density gradient velocity sedimentation. The two membrane fractions obtained from villus cells and considered to be lateral-basal membranes were enriched for Na+,K+-ATPase activity, but one also showed enrichment in glycosyltransferase activity. The Golgi membrane fraction was enriched for glycosyltransferase activity and had low to absent Na+,K+-ATPase activity. Adenylate cyclase activity was present in all membrane fractions except the microvillus membrane but co-purified with Golgi rather than lateral-basal membranes. Electron microscopy showed that the Golgi fraction consisted of variably sized vesicles and cisternalike structures. The two lateral-basal membrane fractions showed only vesicles of smaller, more uniform size. After 125I labeling of isolated intact cells, radioactivity was found associated with the lateral-basal and microvillus membrane fractions and not with the Golgi fraction. Antibody prepared against lateral-basal membrane fractions reacted with the surface membrane of isolated villus cells. The membrane fractions from isolated crypt cells demonstrated that all had high glycosyltransferase activity. The data show that glycosyltransferase activity, in addition to its Golgi location, may be a significant property of the lateral-basal portion of the intestinal villus cell plasma membrane. Data obtained with crypt cells support earlier data and show that the crypt cell surface membrane possesses glycosyltransferase activity.

scholarly journals The surface epithelium of teleostean fish gills. Cellular and junctional adaptations of the chloride cell in relation to salt adaptation.

1979 ◽  
Vol 80 (1) ◽  
pp. 96-117 ◽  
Author(s):  
C Sardet ◽  
M Pisam ◽  
J Maetz
Keyword(s):  
Salt Water ◽  
Freeze Fracture ◽  
Morphological Characteristics ◽  
Chloride Cell ◽  
Chloride Cells ◽  
Surface Epithelium ◽  
Salt Adaptation ◽  
Resistance Pathway ◽  
Shallow Junctions ◽  
Respiratory Cells

Various species of teleostean fishes were adapted to fresh or salt water and their gill surface epithelium was examined using several techniques of electron microscopy. In both fresh and salt water the branchial epithelium is mostly covered by flat respiratory cells. They are characterized by unusual outer membrane fracture faces containing intramembranous particles and pits in various stages of ordered aggregation. Freeze fracture studies showed that the tight junctions between respiratory cells are made of several interconnecting strands, probably representing high resistance junctions. The organization of intramembranous elements and the morphological characteristics of the junctions do not vary in relation to the external salinity. Towards the base of the secondary gill lamellae, the layer of respiratory cells is interrupted by mitochondria-rich cells ("chloride cells"), also linked to respiratory cells by multistranded junctions. There is a fundamental reorganization of the chloride cells associated with salt water adaptation. In salt water young adjacent chloride cells send interdigitations into preexisting chloride cells. The apex of the seawater chloride cell is therefore part of a mosaic of sister cells linked to surrounding respiratory cells by multistranded junctions. The chloride cells are linked to each other by shallow junctions made of only one strand and permeable to lanthanum. It is therefore suggested that salt water adaptation triggers a cellular reorganization of the epithelium in such a way that leaky junctions (a low resistance pathway) appear at the apex of the chloride cells. Chloride cells are characterized by an extensive tubular reticulum which is an extension of the basolateral plasma membrane. It is made of repeating units and is the site of numerous ion pumps. The presence of shallow junctions in sea water-adapted fish makes it possible for the reticulum to contact the external milieu. In contrast in the freshwater-adapted fish the chloride cell's tubular reticulum is separated by deep apical junctions from the external environment. Based on these observations we discuss how solutes could transfer across the epithelium.

New Composite Metal Foams under Compressive Cyclic Loadings

2007 ◽  
Vol 539-543 ◽  
pp. 1868-1873 ◽  
Author(s):  
Afsaneh Rabiei ◽  
Brian Neville ◽  
Nick Reese ◽  
Lakshmi Vendra
Keyword(s):  
Maximum Stress ◽  
Cell Structure ◽  
Hollow Spheres ◽  
Metal Foams ◽  
Entire Sample ◽  
Gravity Casting ◽  
Cyclic Compression ◽  
High Maximum ◽  
Processing Techniques ◽  
Very High

New composite metal foams are processed using powder metallurgy (PM) and gravity casting techniques. The foam is comprised of steel hollow spheres, with the interstitial spaces occupied by a solid metal matrix (Al or steel alloys). The cyclic compression loading of the products of both techniques has shown that the composite metal foams have high cyclic stability at very high maximum stress levels up to 68 MPa. Under cyclic loading, unlike other metal foams, the composite metal foams do not experience rapid strain accumulation within collapse bands and instead, a uniform distribution of deformation happen through the entire sample until the densification strain is reached. This is a result of more uniform cell structure in composite metal foams compared to other metal foams. As a result, the features controlling the fatigue life of the composite metal foams have been considered as sphere wall thickness and diameter, sphere and matrix materials, and processing techniques as well as bonding strength between the spheres and matrix.

Sign in / Sign up

Export Citation Format

Share Document