Apparent Water Permeability Research Articles

Mechanisms Transducing Cell Shrinkage in Xenopus Oocytes † 176

Hypertonicity shrinks cells, which restore their volume by osmolyte uptake. The transduction mechanism leading to osmolyte uptake is not known. Our aim was to determine whether cells transduce H2O loss via distortion of the membrane/cytoskeleton or via increasing concentrations of intracellular ions or macromolecules. We previously showed, in Xenopus oocytes, that hypertonicity induces Ca2+-dependent Cl- currents (Ihi). Both the rate and extent of Ihi are increased by expressing mRNA for the water channel protein aquaporin-1 to speed shrinkage. In order to correlate Ihi activation and cell volume changes, we simultaneously measured Ihi using the 2-electrode voltage clamp, and cell diameter using a video caliper in AQP1-expressing oocytes under three conditions: hypertonic shrinkage, hypertonic exposure at constant cell volume, and isotonic withdrawal of cytoplasm. Cell volume was calculated from cell diameter assuming a spherical shape. Volume was manipulated directly by injecting H2O or withdrawing cytoplasm via a computerized microsyringe connected to a third intracellular micropipette. Increasing bath osmolality (200 to 400 mosm/l) shrunk cells from 2.0 to 1.8 μl and activated Ihi (-55±12 nA at -65 mV). Moreover, hypertonicity activated Ihi before volume changed significantly. Indeed, Ihi activated even when volume was held constant (±0.3%) using feedback controlled injection of H2O. During this “volume clamp”, we observed decreased water flux with time without any change in the apparent water permeability judged from the time elapsed before cell rupture when the bath solution was replaced with distilled water. This suggested an osmotic gradient was established within the cell and is consistent with activation of Ihi by an increase in the concentration of some critical intracellular molecule. Withdrawing 120 nl of cytoplasm did not activate Ihi (n=7). This suggests that membrane deformation alone is not sufficient to activate the current. We conclude that increased ionic/macromolecular concentration beneath the membrane, and not mechanical distortion, activates Ihi.

Apparent water permeability as a physiological parameter in crustaceans

This article reviews the use of apparent water permeability (AWP) calculated from measurements of isotope-labelled water flux as a physiological estimate of whole-body water permeability in aquatic invertebrates. The rationale and practices of AWP calculations are described in an Appendix. AWP calculations have provided a wealth of information. However, the validity of the method and therefore also of the information obtained have been questioned. Consequently, the use of AWP data in discussions of osmotic and fluid homeostatic questions in aquatic invertebrates is limited. This article reviews three decades of published experiments in which measurements of isotope-labelled water fluxes were used to estimate water permeability in aquatic invertebrates. Data on 24 species of arthropod, most of them decapod crustaceans, are presented. The combined data indicate that the results obtained by different investigators on the same species show good agreement, even though different tracers and experimental methods have been applied. When available, results from other kinds of studies were used to evaluate the results obtained using the AWP measurements. The various results demonstrate that AWP is influenced not only by natural environmental factors, such as salinity and temperature, and by anthropogenic factors, such as potentially toxic trace metals, but that it is also regulated by intrinsic factors, such as ecdysis and life cycle stage. The results obtained can often be explained as effects of components of the habitat of the animal. Accordingly, studies on variations in AWP contribute to our understanding of the different physiological strategies used by species living in a changing environment. We conclude that calculations of AWP offer reliable, relevant physiological data in a range of crustacean species, as long as methodological limitations and uncertainties are kept in mind. In addition, we propose some possible new ways of applying AWP calculations to marine invertebrates other than crustaceans. A major part of this review describes results already obtained for the shore crab Carcinus maenas as this species is probably the animal on which most work has been carried out. We suggest topics for future work on this species and review the possibility of using AWP in C. maenas as a biomarker of metal exposure.

The effect of salinity and calcium concentration on the apparent water permeability of Cherax destructor, Astacus astacus and Carcinus maenas (Decapoda, Crustacea)

Abstract The effect of calcium concentration and salinity on the apparent water permeability (AWP) has been investigated in three decapods: the Australian Yabbie (Cherax destructor), the noble crayfish (Astacus astacus) and the shore crab (Carcinus maenas). C. destructor does not change its AWP with changing Ca concentration or salinity. The AWP of A. astacus decreases when animals are acclimated to low and high salinities (0.09 and 24 mM NaCl) compared with intermediate ones (0.36, 0.72 and 6 mM NaCl). At high Ca concentrations (5 mM Ca) salinity does not affect AWP. C. maenas decreases its AWP with decreasing salinity. This decrease is most profound when Ca concentration is low. The observed interspecific differences are discussed in terms of habitat, strategy and evolution.

The effects of trace metals on the apparent water permeability of the shore crab Carcinus maenas (L.) and the brown shrimp Crangon crangon (L.)

The effects of trace metals on the apparent water permeability (AWP) of two decapod crustaceans Carcinus maenas and Crangon crangon, were investigated. One hour exposure to 1 mg l −1 dissolved Hg or Pb significantly decreased the AWP of the shore crab, C. maenas. A similar, but not significant, tendency was observed following exposure to Cd, Cu and Zn, whereas Co had little effect. The AWP of C. maenas exposed to Cd decreased with increasing Cd concentration (0.5, 1, 4 or 8 mg l −1). This decrease was independent of exposure time (1, 5 or 10 days). The influence of Zn (500 μg l −1) on the apparent water permeability of the brown shrimp C. crangon was also investigated. After 24 h exposure to Zn, AWP decreased significantly. This reduction persisted for at least 3 days. After 6 days of exposure, AWP returned to the initial level. Whether trace metal induced changes in the AWP are the result of toxic effects of the metals or represent physiological adaptations minimizing the effects of external perturbations is discussed.

Physiological responses and the uptake of cadmium and zinc by the amphipod crustacean Orchestia gammarellus

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 127:87-102 (1995) - doi:10.3354/meps127087 Physiological responses and the uptake of cadmium and zinc by the amphipod crustacean Orchestia gammarellus Rainbow PS, Kwan MKH The rates of uptake of cadmium and zinc by the amphipod crustacean Orchestia gammarellus (Pallas) increase with decrease in salinity from 36.5 to 25 NaCl, as expected from physico-chemical changes in the availabilities of free metal ions. Between 15 and 25 NaCl cadmium and zinc uptake rates plateau, and the cadmium uptake rate falls at 12 NaCl. This pattern of change of uptake rate with salinity change is not dependent on trace metal exposure concentrations, and cannot be explained by uptake via any enzyme-driven uptake route. It is concluded that at low salinity the amphipods effect one or more physiological responses that offset any increases in cadmium and zinc uptake rates expected from physico-chemical increases in the availabilities of free metal ions at low salinity. Such physiological responses are induced by changes in total osmolality, as opposed to inorganic salinity, and are not maintained on transfer from low to high osmolality. The physiological response is not explicable only in terms of change of the uptake rate of calcium, nor only in terms of change in apparent water permeability which may play a role at extremely low salinities. In low salinity the amphipods do excrete newly accumulated cadmium and zinc but this excretion does not explain the lack of increase in net uptake of cadmium and zinc at low salinities. The identification of the physiological response of O. gammarellus reducing trace metal uptake at low salinity remains enigmatic, and may turn out to be combination of several effects. Trace metal . Heavy metal . Cadmium . Uptake . Salinity . Osmolality . Water permeability . Calcium pump . Orchestia . Amphipod crustacean Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 127. Publication date: November 02, 1995 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1995 Inter-Research.

Physicochemical and physiological effects on the uptake of dissolved zinc and cadmium by the amphipod crustacean Orchestia gammarellus

An artificial medium of NaCl in distilled water, of predictable dissolved metal speciation equilibria, has been used to define the effects of physicochemical changes on the uptake of zinc (Zn) and cadmium (Cd) by the euryhaline littoral amphipod crustacean Orchestia gammarellus (Pallas). At salinities between 36.5 and 25‰, changes in uptake rate of either metal correlated with predicted changes in free metal ion concentrations upon change in salinity, indicating the dominant role of medium physicochemistry in defining metal uptake rates. At 15‰ salinity, however, the change in uptake rate of each metal was no longer proportional to the change in free metal ion concentration, indicating a physiological response on the part of the amphipod to low salinity. It is proposed that such a response might be a reduction in apparent water permeability, characteristic of some euryhaline crustaceans. It is concluded that the use of a simple medium of defined physicochemistry has permitted the resolution of physicochemical and physiological effects on trace metal uptake rates, and that physiological adaptations of euryhaline organisms are significant in determining rates of trace metal uptake.

Effect of atrial natriuretic factor on the water permeability of endothelial cells

Atrial natriuretic factor increases the water permeability of the whole endothelium. This study investigates how it would affect the transcellular osmotic water permeability of bovine artery endothelial cells. The cyclic-GMP production by the isolated cells was maximal for 10(-6)M atrial natriuretic factor within 30 minutes at 37 degrees C. The cyclic-GMP protein kinase cell concentration was 1.87 +/- 0.15 ng/mg protein. The control apparent water permeability of the cells measured by light scattering was 195 +/- 11 microns/sec (n = 5). Membrane folding revealed by light and scanning electron microscopy indicated that their true water permeability values would be close to 20-40 microns/sec, similar to the values for lipid membranes. The energy activation calculated from the temperature dependence of water permeability between 15 degrees C and 37 degrees C was 9.3 kcal/mol. This value suggests water movement through the lipid bilayer and not through water channels. Atrial natriuretic factor 10(-6)M did not significantly increase the water permeability of the cells. Hence, atrial natriuretic factor-stimulated increase in water permeability of the endothelium is more related to changes in paracellular water pathways than in transcellular water flux.

Uptake of zinc and cadmium by two different populations of shore crabs Carcinus maenus at different salinities

Effects of salinity on the accumulation of Zn and Cd in the haemolymph (relative indices of Zn and Cd uptake rates) of 2 populations of shore crab Carcinus maenas (L.) were investigated. Zn accumulation rates in the haemolymph of the Scottish (high salinity) crabs were higher than those of the Danish (low salinity) crabs. Decreases in salinity significantly decreased the Zn accumulation rate in the Scottish crabs but increases in salinity did not change the Zn accumulation rates in the Danish crabs significantly. Scottish crabs also showed a higher Cd accumulation rate, as well as elimination rate, than those of the Danish crabs. The highest Cd accumulation rate in Scottish crabs was found at 33 ppt salinity. In contrast the Cd accumulation rate of Danish crabs was highest at 15 ppt. It is proposed that exposure of the crabs to low salinity probably involves changes to crab permeability (e.g. apparent water permeability), thereby off-setting physico-chemical changes promoting the availabilities of free zinc and cadmium ions in solution which would otherwise increase metal uptake rates.

Osmotic forces driving water reabsorption in the proximal tubule of the rat kidney.

Simultaneous microperfusion of proximal tubules and peritubular capillaries in kidneys of rats anesthetized with Inactin was used to measure reabsorption of fluid in response to an imposed osmotic gradient. The tubular fluid was isotonic and the peritubular capillaries were made hypertonic with NaCl or NaHCO3. Mean gradients and ionic fluxes were measured. When no gradient was imposed tubular fluid became hypotonic and rate of fluid reabsorption was 0.700 nl.mm-1.min-1. Imposition of a 25 mM NaCl gradient increased fluid flux to 3.887 nl.mm-1.min-1, whereas 25 mM NaHCO3 stimulated 5.226 ml/mm fluid reabsorption. This gave a relative reflection coefficient of NaCl:NaHCO3 of 0.73. Apparent water permeability varied with highest values for the smallest gradients. This suggests the possibility of a compartment in the epithelium that is hypertonic to the peritubular capillaries. The hypertonicity required to account for fluid movement was 6-16 mosmol/kg.

Conductivity and water permeability of barrier-layer AlCl 3 as a function of temperature

Corrosion experiments were performed with a shielded electrode of 99.999% aluminum in the anode facing up position in saturated aluminum chloride at temperatures of 20–90°C to obtain properties of the barrier-layer AlCl 3 film. High-field conduction parameters and hydrogen current density were determined as a function of temperature. Apparent water permeability coefficient through the film based on hydrogen current density and its activation energy were evaluated.

Regulation of ADH-stimulated water flow at a post-luminal barrier in toad bladder.

Recent studies show that ADH-stimulated water flow across toad bladder may be regulated at a site other than the luminal membrane. In these studies luminal membrane particle aggregate frequency has been used as a measure of luminal membrane water permeability. In fully stretched bladders the relationship between total tissue permeability and aggregate frequency is curvilinear, rather than linear. This implies a resistance in series with the luminal membrane that can become rate-limiting for water flow during ADH stimulation. The possibility that transtissue water movement is actually regulated at such a post-luminal membrane resistance is suggested by the finding that within 30 min following exposure to hormone, water flow becomes attenuated without any change in aggregate frequency. Supporting this possibility, recent data from follow-up studies suggest that the apparent water permeability per luminal membrane aggregate is not reduced with time. Finally, for bladders in which prostaglandin synthesis is inhibited (by naproxen), increases in both base-line water flow and water flow consequent to treatment with a submaximal dose of ADH (0.125 mU/ml), are much less than expected from simultaneously observed changes in luminal membrane aggregate frequency. In parallel experiments to these, moreover, direct measurements of luminal membrane water permeability from the rate of change of cell volume consequent to a transluminal membrane osmotic challenge, confirm that luminal membrane water permeability increases to the extent expected from changes in aggregate frequency. All of the data taken together argue for a post-luminal membrane barrier in toad bladder which regulates tissue permeability during ADH stimulation.

Apparent water permeability and hemolymph acid phosphatase activity as indices of stress in the estuarine grass shrimp, Palaemonetes pugio

1. Apparent water permeability and hemolymph acid phosphatase activity were determined in shrimp exposed for 32 days to fluctuating temperatures and to food contaminated with the aromatic hydrocarbon, dimethylnaphthalene. Both indices were determined again following a 16-day recovery period in which uncontaminated food was provided to shrimp in a stable temperature environment. 2. Fluctuating temperatures induced diminished apparent water permeability after both the exposure and the recovery periods. This decrease was offset by the ingestion of contaminated food. Contaminated food alone had no effect on apparent water permeability. All shrimp exhibited a uniform increase in apparent water permeability following the recovery period. 3. Shrimp exposed to fluctuating temperatures had significantly elevated enzyme activities when subjected to hypoxic conditions, compared to shrimp held in stable temperatures. Ingestion of contaminated food had no detectable effect on enzyme activities. 4. After the recovery period, shrimp which had previously ingested contaminated food had lower enzyme activities when exposed to hypoxic conditions than shrimp which had ingested nothing but uncontaminated food. Fluctuating temperatures had no residual effect on enzyme activity in shrimp exposed to hypoxic conditions.

Effect of distension on ADH-induced osmotic water flow in toad urinary bladder.

We recently described a method by which the resistance to water flow of the luminal membrane of ADH-stimulated toad bladder can be quantitatively distinguished from that of barriers lying in series with it. This method requires estimated of both total bladder water permeability (assessed by transbladder osmotic water flow at constant gradient) and luminal membrane water permeability (assessed by quantitation of the frequency of ADH-induced luminal membrane particle aggregates). In the present study we examined the effect of bladder distension on transepithelial osmotic water flow before and during maximal ADH stimulation. Base-line water flow was unaffected by bladder distension, but hormonally stimulated flow increased systematically as bladders became more distended. Distension had no effect on the frequency of ADH-induced intramembranous particle aggregates. By comparing the relationships between aggregate frequency and hormonally induced water permeability in distended and undistended bladders, we found that distension appeared to enhance ADH-stimulated water flow by decreasing the resistance of the series permeability barrier while the apparent water permeability associated with each single luminal membrane aggregate was unaffected. In that bladder distension caused tissue thinning, the series resistance limiting ADH-stimulated water flow appears to be accounted for by deformable barriers within the bladder tissue itself, probably unstirred layers of water.

A Study of the Water Permeability of the Gills of Freshwater- and Seawater-adapted Trout (Salmo gairdneri): Mode of Action of Epinephrine

Water permeability of trout gills (Salmo gairdneri) was studied in vitro with fish adapted to freshwater (FW) and to seawater (SW). In adapted fish, diffusional water permeability is less in SW than in FW, whereas the apparent osmotic water permeability is invariant. The ratio of osmotic to diffusional water permeabilities is greater than unity. This result demonstrates the existence of two water transfer mechanisms, diffusion and bulk transport. Osmotic permeability is increased threefold by an instantaneous change of external salinity, while diffusional permeability remains unchanged under the same circumstances. The addition of 10⁻⁶M epinephrine to the perfusion liquid leads to an increase of diffusional permeability in FW-adapted fish (+110%) and in SW-adapted individuals (+60%). Osmotic permeability increases in both cases (+30%). In the course of rapid transfer experiments, epinephrine does not modify the behavior of diffusional fluxes, while it does attenuate the osmotic flux rectification mechanis...

Changes in apparent water permeability during the moulting cycle in the western rock lobster

The kinetics of water exchange, as measured by 3H 2O fluxes, were examined in the western rock lobster, Panulirus longipes (Milne Edwards) during stages C 4, D 3, D 4, D 4-E and B 1 of the moulting cycle. A series of samples of blood and external water was taken during each experiment and the inward and outward rate constants found using the SAAM 25 computer program, assuming a simple 2-compartment model with reversible exchange. Both inward and outward turnover rates remained constant up to the swelling prior to ecdysis when there was an increase of 203% inwards compared with 133% outwards. The latter increased in stage B 1, so that both rates were comparably high, probably due to the increased permeability of the soft integument. Further analysis showed that the rock lobster does not behave as a single compartment with respect to tritiated water. Two compartments were resolved by graphical analysis, one with fast and the other with slow exchange. It is suggested that blood and tissue ‘free’ water comprise one compartment and chemically ‘bound’ water the other, with fast exchange between the free and bound water and relatively slow exchange between free body water and the external medium.

Effects of brain removal on integumental water permeability and ion content of the earthworm Lumbricus terrestris L

The apparent integumental water permeability of nonhydrated Lumbricus terrestris is significantly greater than that of fully hydrated earthworms, which may act to reduce water losses in the soil. Apparent water permeability is significantly greater in decerebrate Lumbricus than in control worms. Hourly water exchange values ( K) are 2.28 for brainless and 1.71 for intact animals. Weight regulation in water and dehydration rates are the same in decerebrate and in control worms. However, when dehydrated and subsequently replaced in water, brainless animals have a 70% greater hydration rate and gain more weight than do control animals. Both total osmotic pressure and Cl − content of the coelomic fluid of fully hydrated earthworms are lower in brainless than in control animals. Brain removal tends to increase osmotic pressure in dehyrated Lumbricus, although not to a significant degree. Although the effects of brain removal suggest a neuroendocrine control of integumental water permeability in Lumbricus, the failure of reimplanted brains to have an effect leaves the hypothesis of such a control incompletely verified.

Sodium and Water Permeabilities in Selected Crustacea

Previous articleNext article No AccessSodium and Water Permeabilities in Selected CrustaceaA. SubramanianA. Subramanian Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 48, Number 4Oct., 1975 Article DOIhttps://doi.org/10.1086/physzool.48.4.30155665 Views: 2Total views on this site Citations: 9Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). PDF download Crossref reports the following articles citing this article:Carolina A. Freire, Enelise M. Amado, Luciana R. Souza, Marcos P.T. Veiga, Jean R.S. Vitule, Marta M. Souza, Viviane Prodocimo Muscle water control in crustaceans and fishes as a function of habitat, osmoregulatory capacity, and degree of euryhalinity, Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 149, no.44 (Apr 2008): 435–446.https://doi.org/10.1016/j.cbpa.2008.02.003A.V Frolov, S.L Pankov, K.N Geradze, S.A Pankova Influence of salinity on the biochemical composition of the rotifer Brachionus plicatilis (Muller). aspects of adaptation, Comparative Biochemistry and Physiology Part A: Physiology 99, no.44 (Jan 1991): 541–550.https://doi.org/10.1016/0300-9629(91)90129-ZMichael J. Sommer, Linda H. Mantel Effect of dopamine, cyclic AMP, and pericardial organs on sodium uptake and Na/K-ATPase activity in gills of the green crabCarcinus maenas (L), Journal of Experimental Zoology 248, no.33 (Dec 1988): 272–277.https://doi.org/10.1002/jez.1402480305Thomas G. Wolcott, Donna L. Wolcott Extrarenal modification of urine for ion conservation in ghost crabs, Ucypode quadrata (Fabricius), Journal of Experimental Marine Biology and Ecology 91, no.1-21-2 (Sep 1985): 93–107.https://doi.org/10.1016/0022-0981(85)90223-0C.R.B.Che Mat, W.T.W Potts Water balance in Crangon vulgaris, Comparative Biochemistry and Physiology Part A: Physiology 82, no.33 (Jan 1985): 705–710.https://doi.org/10.1016/0300-9629(85)90455-4T.M. Dillon, Daniel J. Fisher Apparent water permeability and hemolymph acid phosphatase activity as indices of stress in the estuarine grass shrimp, Palaemonetes pugio, Comparative Biochemistry and Physiology Part C: Comparative Pharmacology 74, no.22 (Jan 1983): 377–382.https://doi.org/10.1016/0742-8413(83)90118-4G.D. Robinson Water fluxes and urine production in blue crabs (Callinectes sapidus) as a function of environmental salinity, Comparative Biochemistry and Physiology Part A: Physiology 71, no.33 (Jan 1982): 407–412.https://doi.org/10.1016/0300-9629(82)90426-1Larry C. Oglesby Volume regulation in aquatic invertebrates, Journal of Experimental Zoology 215, no.33 (Mar 1981): 289–301.https://doi.org/10.1002/jez.1402150307W. Dall, D.M. Smith Changes in apparent water permeability during the moulting cycle in the western rock lobster, Journal of Experimental Marine Biology and Ecology 34, no.11 (Jan 1978): 43–54.https://doi.org/10.1016/0022-0981(78)90056-4