scholarly journals Immunochemical analysis of the vacuolar proton-ATPase B-subunit in the gills of a euryhaline stingray (Dasyatis sabina): effects of salinity and relation to Na+/K+-ATPase

2001 ◽  
Vol 204 (19) ◽  
pp. 3251-3259 ◽  
Author(s):  
Peter M. Piermarini ◽  
David H. Evans
Keyword(s):  
Sea Water ◽  
Basolateral Membrane ◽  
Teleost Fishes ◽  
Pavement Cells ◽  
B Subunit ◽  
Dasyatis Sabina ◽  
Proton Atpase ◽  
Elasmobranch Fishes ◽  
Atpase Localization ◽  
Na Uptake

SUMMARY In the gills of freshwater teleost fishes, vacuolar proton-ATPase (V-H+-ATPase) is found on the apical membrane of pavement and chloride (Na+/K+-ATPase-rich) cells, and is an important transporter for energizing Na+ uptake and H+ excretion. In the gills of elasmobranch fishes, the V-H+-ATPase has not been extensively studied and its expression in freshwater individuals has not been examined. The goals of this study were to examine the effects of environmental salinity on the expression of V-H+-ATPase in the gills of an elasmobranch (the Atlantic stingray, Dasyatis sabina) and determine if V-H+-ATPase and Na+/K+-ATPase are expressed in the same cells. We found that gills from freshwater stingrays had the highest relative abundance of V-H+-ATPase and greatest number of V-H+-ATPase-rich cells, using immunoblotting and immunohistochemistry, respectively. When freshwater animals were acclimated to sea water for 1 week, V-H+-ATPase abundance and the number of V-H+-ATPase-rich cells decreased significantly. Atlantic stingrays from seawater environments were characterized by the lowest expression of V-H+-ATPase and least number of V-H+-ATPase-rich cells. In contrast to teleost fishes, localization of V-H+-ATPase in freshwater stingray gills was not found in pavement cells and occurred on the basolateral membrane in cells that are presumably rich in mitochondria. In freshwater stingrays acclimated to sea water and seawater stingrays, V-H+-ATPase localization appeared qualitatively to be stronger in the cytoplasm, which may suggest the transporter was stored in vesicles. Using a double-immunolabeling technique, we found that V-H+-ATPase and Na+/K+-ATPase occurred in distinct cells, which suggests there may be two types of mitochondrion-rich cells in the elasmobranch gill epithelium. Based on these findings, we propose a unique model of NaCl and acid–base regulation where the V-H+-ATPase-rich cells and Na+/K+-ATPase-rich cells are the sites of Cl– uptake/HCO3– excretion and Na+ uptake/H+ excretion, respectively.

scholarly journals Redistribution of immunofluorescence of CFTR anion channel and NKCC cotransporter in chloride cells during adaptation of the killifish Fundulus heteroclitus to sea water

2002 ◽  
Vol 205 (9) ◽  
pp. 1265-1273 ◽  
Author(s):  
W. S. Marshall ◽  
E. M. Lynch ◽  
R. R. F. Cozzi
Keyword(s):  
Fundulus Heteroclitus ◽  
Apical Membrane ◽  
Sea Water ◽  
Basolateral Membrane ◽  
Anion Channel ◽  
Chloride Cells ◽  
Transmembrane Conductance Regulator ◽  
Pavement Cells ◽  
Cell Complexes ◽  
C Terminus

SUMMARY Cellular distribution of cystic fibrosis transmembrane conductance regulator (CFTR) immunofluorescence was detected by monoclonal antibody directed to the C terminus of killifish CFTR (kfCFTR) in chloride cells of fresh water (FW) adapted fish and animals transferred to sea water (SW) for 24h, 48h and 14+ days. Confocal microscopy allowed localization within mitochondria-rich (MR) cells to be determined as superficial (i.e. in the apical membrane) or deeper within the cytoplasm of the cells. In FW, 90 % of MR cells had diffuse kfCFTR immunofluorescence in the central part of the cytosol, with only 8.1 % having apical kfCFTR, which was 6.6±0.54 μm below the microridges of surrounding pavement cells. Curiously, FW but not SW pavement cells also had positive immunofluorescence to kfCFTR. After 24h in SW, a time when kfCFTR expression is elevated, a condensed punctate immunofluorescence appeared among 18.8 % of MR cells, 13.4±0.66 μm(mean ± S.E.M.) below the surface of the cells. By 48h, a majority(76.3 %) of MR cells had punctate kfCFTR distribution and the distance from the surface was less (7.8±0.2 μm), a distribution approaching the SW-acclimated condition (i.e. all MR cells showing kfCFTR immunofluorescence,6.1±0.04 μm below the surface). In contrast, NKCC immunofluorescence was condensed and localized in lateral parts of MR cell complexes in FW animals and then redistributed to the whole basal cytoplasm after acclimation to SW. CFTR, the anion channel responsible for Cl- secretion in marine teleosts, redistributes in MR cells during SW acclimation by condensation of a diffuse distribution below the apical crypt, followed by translocation and insertion in the apical membrane. NKCC, the cotransporter that translocates Cl- across the basolateral membrane, moves from an eccentric cytosolic location in FW to a diffuse basolateral localization in SW chloride cells.

scholarly journals Elevated carbon dioxide alters the plasma composition and behaviour of a shark

2014 ◽  
Vol 10 (9) ◽  
pp. 20140538 ◽  
Author(s):  
Leon Green ◽  
Fredrik Jutfelt
Keyword(s):  
Ocean Acidification ◽  
Fossil Fuels ◽  
Resting Metabolic Rate ◽  
Blood Chemistry ◽  
Teleost Fishes ◽  
Behavioural Effects ◽  
Swimming Pattern ◽  
Acclimation Period ◽  
Elevated Water ◽  
Elasmobranch Fishes

Increased carbon emissions from fossil fuels are increasing the p CO 2 of the ocean surface waters in a process called ocean acidification. Elevated water p CO 2 can induce physiological and behavioural effects in teleost fishes, although there appear to be large differences in sensitivity between species. There is currently no information available on the possible responses to future ocean acidification in elasmobranch fishes. We exposed small-spotted catsharks ( Scyliorhinus canicula ) to either control conditions or a year 2100 scenario of 990 μatm p CO 2 for four weeks. We did not detect treatment effects on growth, resting metabolic rate, aerobic scope, skin denticle ultrastructure or skin denticle morphology. However, we found that the elevated p CO 2 group buffered internal acidosis via accumulation with an associated increase in Na + , indicating that the blood chemistry remained altered despite the long acclimation period. The elevated p CO 2 group also exhibited a shift in their nocturnal swimming pattern from a pattern of many starts and stops to more continuous swimming. Although CO 2 -exposed teleost fishes can display reduced behavioural asymmetry (lateralization), the CO 2 -exposed sharks showed increased lateralization. These behavioural effects may suggest that elasmobranch neurophysiology is affected by CO 2 , as in some teleosts, or that the sharks detect CO 2 as a constant stressor, which leads to altered behaviour. The potential direct effects of ocean acidification should henceforth be considered when assessing future anthropogenic effects on sharks.

Pendrin immunoreactivity in the gill epithelium of a euryhaline elasmobranch

2002 ◽  
Vol 283 (4) ◽  
pp. R983-R992 ◽  
Author(s):  
Peter M. Piermarini ◽  
Jill W. Verlander ◽  
Ines E. Royaux ◽  
David H. Evans
Keyword(s):  
Collecting Duct ◽  
Apical Region ◽  
Intercalated Cells ◽  
Cortical Collecting Duct ◽  
Gill Epithelium ◽  
Dasyatis Sabina ◽  
Proton Atpase ◽  
Atlantic Stingray ◽  
Freshwater Stingray ◽  
Gill Lamellae

Pendrin is an anion exchanger in the cortical collecting duct of the mammalian nephron that appears to mediate apical Cl−/HCO[Formula: see text]exchange in bicarbonate-secreting intercalated cells. The goals of this study were to determine 1) if pendrin immunoreactivity was present in the gills of a euryhaline elasmobranch (Atlantic stingray, Dasyatis sabina), and 2) if branchial pendrin immunoreactivity was influenced by environmental salinity. Immunoblots detected pendrin immunoreactivity in Atlantic stingray gills; pendrin immunoreactivity was greatest in freshwater stingrays compared with freshwater stingrays acclimated to seawater (seawater acclimated) and marine stingrays. Using immunohistochemistry, pendrin-positive cells were detected on both gill lamellae and interlamellar regions of freshwater stingrays but were more restricted to interlamellar regions in seawater-acclimated and marine stingray gills. Pendrin immunolabeling in freshwater stingray gills was more apical, discrete, and intense compared with seawater-acclimated and marine stingrays. Regardless of salinity, pendrin immunoreactivity occurred on the apical region of cells rich with basolateral vacuolar-proton-ATPase, and not in Na+-K+-ATPase-rich cells. We suggest that a pendrin-like transporter may contribute to apical Cl−/HCO[Formula: see text] exchange in gills of Atlantic stingrays from both freshwater and marine environments.

Characterization of a distinct Na(+)-H+ exchanger in basolateral membranes of human jejunum

1993 ◽  
Vol 264 (1) ◽  
pp. G45-G50
Author(s):  
S. Acra ◽  
W. Dykes ◽  
W. Nylander ◽  
F. K. Ghishan
Keyword(s):  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Kinetic Studies ◽  
Maximal Velocity ◽  
Nacl Transport ◽  
Human Organ ◽  
Basolateral Membranes ◽  
Plot Analysis ◽  
Gradient Technique ◽  
Na Uptake

Kinetically distinct Na(+)-H+ exchangers exist on the apical and basolateral membranes of rabbit ileal enterocytes. The apical Na(+)-H+ exchanger appears to function in electroneutral NaCl transport, whereas the basolateral Na(+)-H+ exchanger may function in homeostatic intravesicular pH (pHi) regulation and volume regulation. This study is designed to determine the presence and characteristics of the Na(+)-H+ exchanger in basolateral membrane vesicles (BLMV) prepared from jejunal tissues of human organ donors. A well-validated Percoll-gradient technique was used to prepare BLMV. An outwardly directed H+ gradient [pHi/extravesicular pH (pHo) = 5.2/7.5] resulted in a Na+ uptake overshoot (1.45 +/- 0.21 nmol/mg protein) 2.5-fold above equilibrium values (0.59 +/- 0.13 nmol/mg protein). Na+ uptake at equilibrium represented transport into an osmotically sensitive intravesicular space as validated by an osmolality study. Na+ uptake represented an electroneutral process, as shown by studies in which negative membrane potentials were induced by K+ and the ionophore valinomycin. Na+ uptake was linear for the first 15 s of transport as depicted by y = 0.042x + 0.002, r2 = 0.98. Dixon plot analysis of amiloride sensitivity revealed an ID50 value for amiloride of 29 microM (fourfold lower than ID50 for brush-border Na(+)-H+ exchanger). Kinetic studies of amiloride-sensitive Na+ uptake revealed a maximal velocity = 1.53 +/- 0.19 nmol.mg protein-1.5 s-1 and Michaelis constant = 9.83 +/- 3.5 mM. By varying pHi a sigmoidal effect of internal H+ on Na+ uptake was noted consistent with an internal modifier site for protons. To confirm this finding, the effect of pHi on Na+ efflux and Na(+)-Na+ exchange was studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid redistribution and inhibition of renal sodium transporters during acute pressure natriuresis

1996 ◽  
Vol 270 (6) ◽  
pp. F1004-F1014 ◽  
Author(s):  
Y. Zhang ◽  
A. K. Mircheff ◽  
C. B. Hensley ◽  
C. E. Magyar ◽  
D. G. Warnock ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Gradient Centrifugation ◽  
Basolateral Membrane ◽  
Tubuloglomerular Feedback ◽  
Intracellular Membrane ◽  
Acute Hypertension ◽  
Sodium Transporters ◽  
Pump Activity ◽  
Pressure Natriuresis ◽  
Na Uptake

Acute arterial hypertension provokes a rapid decrease in proximal tubule (PT) Na+ reabsorption, increasing flow to the macula densa, the signal for tubuloglomerular feedback. We tested the hypothesis, in rats, that Na+ transport is decreased due to rapid redistribution of apical Na+/H+ exchangers and basolateral Na+ pumps to internal membranes. Arterial pressure was increased 50 mmHg by constricting various arteries. We also tested whether transporter internalization occurred when PT Na+ reabsorption was inhibited with the carbonic anhydrase inhibitor benzolamide. Five minutes after initiating either natriuretic stimuli, cortex was removed, and membranes were fractionated by density gradient centrifugation. Urine output and endogenous lithium clearance increased threefold in response to either stimuli. Acute hypertension provoked a redistribution of apical Na+/H+ exchanger NHE3, alkaline phosphatase, and dipeptidyl peptidase IV to higher density membranes enriched in the intracellular membrane markers. Basolateral membrane Na(+)-K(+)-adenosinetriphosphatase (Na(+)-K(+)-ATPase) activity decreased 50%, 25-30% of the alpha 1-and beta 1-subunits redistributed to higher density membranes, and the remainder is attributed to decreased activity of the transporters. Benzolamide did not alter Na+ transporter activity or distribution, implying that decreasing apical Na+ uptake does not initiate redistribution or inhibition of basolateral Na(+)-K(+)-ATPase. We conclude that PT natriuresis provoked by acute arterial pressure is mediated by both endocytic removal of apical Na+/H+ exchangers and basolateral Na+ pumps as well as decreased total Na+ pump activity.

Further Evidence for Na/NH, Exchange in Marine Teleost Fish

1977 ◽  
Vol 70 (1) ◽  
pp. 213-220
Author(s):  
DAVID H. EVANS
Keyword(s):  
Teleost Fish ◽  
Sea Water ◽  
External Solution ◽  
Marine Teleost ◽  
Exchange System ◽  
Opsanus Beta ◽  
Transepithelial Potential ◽  
Na Uptake ◽  
Marine Teleost Fish

1. Four species of marine teleosts were shown to possess an external-NH4-inhibited Na uptake from 1 mM-NaCl solutions. The inhibition was not due to changes in the transepithelial potential. 2. Injection of 2 μM-NH4/g fish stimulated Na uptake by Opsanus beta and also stimulated ammonia efflux, 50% of which was dependent upon external Na. 3. The ammonia efflux from three species was partially dependent upon external Na. 4. Na/NH4 exchange in O. beta could be reversed so that 22Na efflux could be stimulated by the addition of 200 mM-NH4 to the external solution. 5. These studies show clearly that marine teleosts possess an Na/NH4 exchange system in sea water which results in a net influx of Na into the fish.

The role of environmental calcium in freshwater survival of the marine teleost, Lagodon rhomboides

1976 ◽  
Vol 65 (3) ◽  
pp. 529-538
Author(s):  
J. C. Carrier ◽  
D. H. Evans
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Chelating Agent ◽  
Marine Teleost ◽  
Lagodon Rhomboides ◽  
Na Efflux ◽  
Total Body ◽  
Na Uptake ◽  
Marine Teleost Fish

(1) The marine teleost fish, Lagodon rhomboides, can only tolerate fresh water (5 mM Na) if Ca is also present (10 mM). Transfer to Ca-free fresh water is followed by a substantial increase in radioactive Na efflux with little or no change in the transepithelial potential. Addition of the chelating agent EDTA (2 mM) further increases Na efflux. Fish left in Ca-free fresh water for 2-5 h die with a total body Na less than 50% of that found in animals acclimated to Ca-supplemented fresh water. (2) Rates of Na uptake were measured on either sea-water-acclimated or Ca-supplemented fresh water-acclimated fish transferred to various low Na media. In both cases Na uptake has a high Km, is saturable, inhibited by external NH4, H and amiloride, and is not related to changes in the trans-epithelial potential. (3) It is suggested that L. rhomboides is dependent upon external Ca to decrease diffusional Na loss in low salinities so that a relatively inefficient Na uptake can balance diffusional and urinary Na loss.

Estimation and analysis of biological parameters in elasmobranch fishes: a comparative life history study

2001 ◽  
Vol 58 (5) ◽  
pp. 969-981 ◽  
Author(s):  
Michael G Frisk ◽  
Thomas J Miller ◽  
Michael J Fogarty
Keyword(s):  
Life History ◽  
Population Decline ◽  
Life History Strategies ◽  
Teleost Fishes ◽  
Empirical Relationships ◽  
Lower Growth ◽  
Elasmobranch Species ◽  
Potential Population ◽  
Elasmobranch Fishes ◽  
Life History Study

Published life-history parameters for sharks, skates, and rays over a wide geographic range were used to develop predictive models to estimate parameters that are difficult to measure or have not been previously estimated in elasmobranch species. We determined empirical relationships between body size (total length) and length at maturity (Lm) and age at maturity (Tm). The data used in determining these empirical relationships, the von Bertalanffy parameters asymptotic length (L[Formula: see text]) and growth rate (k), and natural mortality (M) and maximum age (Tmax) were used to describe the life-history strategies of elasmobranch fishes. M/k and Beverton's growth–maturity–longevity plots were used to make comparisons between teleost fishes, reptiles, and elasmobranchs. We found that the M/k ratio in elasmobranchs is significantly different from those for other fish and reptile taxa. We linked elasmobranch species fecundity (f) and Tm to potential vulnerability to population decline under exploitation. We found that larger species of elasmobranchs have lower growth rates (k) and potential population increases (r'). Elasmobranchs can be categorized by species maximum length to determine susceptibility of decline under exploitation. Generally, species greater than 100 cm are characterized by life-history and population traits that place them at greater risk of population decline.

scholarly journals Description of the mechanoreceptive lateral line and electroreceptive ampullary systems in the freshwater whipray, Himantura dalyensis

2011 ◽  
Vol 62 (6) ◽  
pp. 771 ◽  
Author(s):  
Teagan A. Marzullo ◽  
Barbara E. Wueringer ◽  
Lyle Squire Jnr ◽  
Shaun P. Collin
Keyword(s):  
Lateral Line ◽  
Related Species ◽  
Sensory Systems ◽  
Low Salinity ◽  
Dasyatis Sabina ◽  
Estuarine Species ◽  
Ampullae Of Lorenzini ◽  
Infraorbital Canal ◽  
Elasmobranch Species ◽  
Elasmobranch Fishes

Mechanoreceptive and electroreceptive anatomical specialisations in freshwater elasmobranch fishes are largely unknown. The freshwater whipray, Himantura dalyensis, is one of a few Australian elasmobranch species that occur in low salinity (oligohaline) environments. The distribution and morphology of the mechanoreceptive lateral line and the electroreceptive ampullae of Lorenzini were investigated by dissection and compared with previous studies on related species. The distribution of the pit organs resembles that of a marine ray, Dasyatis sabina, although their orientation differs. The lateral line canals of H. dalyensis are distributed similarly compared with two marine relatives, H. gerrardi and D. sabina. However, convolutions of the ventral canals and proliferations of the infraorbital canal are more extensive in H. dalyensis than H. gerrardi. The intricate nature of the ventral, non-pored canals suggests a mechanotactile function, as previously demonstrated in D. sabina. The ampullary system of H. dalyensis is not typical of an obligate freshwater elasmobranch (i.e. H. signifer), and its morphology and pore distribution resembles those of marine dasyatids. These results suggest that H. dalyensis is euryhaline, with sensory systems adapted similarly to those described in marine and estuarine species.

scholarly journals Granulocyte Colony-Stimulating Factor Upregulates the Vacuolar Proton ATPase in Human Neutrophils

Blood ◽  
1997 ◽  
Vol 90 (11) ◽  
pp. 4598-4601 ◽  
Author(s):  
Hans Niessen ◽  
Grant W. Meisenholder ◽  
Hai-Ling Li ◽  
Stephen L. Gluck ◽  
Beth S. Lee ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Human Neutrophils ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
B Subunit ◽  
Proton Atpase ◽  
Atpase Subunits ◽  
Nuclear Changes ◽  
Stimulating Factor

Abstract We have previously shown that granulocyte colony-stimulating factor (G-CSF ) delays spontaneous neutrophil apoptosis through activation of the vacuolar proton ATPase (v-ATPase). We have now examined the regulation of the v-ATPase in neutrophils exposed to G-CSF in vitro. When neutrophils were cultivated in the absence of G-CSF, the 57-kD cytosolic B subunit of the v-ATPase disappeared within 1 to 2 hours, its loss preceding the nuclear changes of apoptosis and coinciding with the onset of acidification. By contrast, in neutrophils cultured for 2 hours in the presence of G-CSF, the amount of the 57-kD subunit was similar to that in freshly isolated neutrophils. However, inhibition of protein synthesis with cycloheximide and actinomycin D led to loss of the 57-kD subunit even in the presence of G-CSF. These results indicated that ongoing protein synthesis was required to maintain the v-ATPase, and further suggested that G-CSF acted, at least in part, by maintaining synthesis of the 57-kD cytosolic subunit. G-CSF also promoted the translocation of the 57-and 33-kD cytosolic v-ATPase subunits to the membrane. Our findings suggested two coordinate mechanisms by which the activity of the v-ATPase could be increased by G-CSF: the synthesis of cytosolic v-ATPase subunits and their translocation to the membrane.

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