scholarly journals Chloride transport in toad skin (Bufo viridis). The effect of salt adaptation

1984 ◽  
Vol 109 (1) ◽  
pp. 353-371 ◽  
Author(s):  
U. Katz ◽  
E. H. Larsen
Keyword(s):  
Chloride Transport ◽  
Tap Water ◽  
Phosphodiesterase Inhibitor ◽  
Flux Ratio ◽  
Salt Adaptation ◽  
Nacl Solution ◽  
Bufo Viridis ◽  
Spontaneous Potential ◽  
Activated State ◽  
Cl Conductance

The steady-state Cl- current across the skin of Bufo viridis adapted to tap water was found to be rectified. In skins bathed with NaCl Ringer on both sides, a large outward current, carried by influx of Cl-, was observed at a clamping voltage (V) of less than −50 mV (outside of the skin negative). for V = −50 mV the transepithelial Cl- conductance calculated from isotope flux measurements was 2.5 +/− 0.3 mS cm-2, N = 10. When the skin was clamped at + 50 mV the net flux of Cl- was reversed, but Cl- conductance was only 0.3 +/− 0.1 mScm-2. Flux ratio analysis indicated that the potential-activated Cl- conductance carries Cl- ions by way of passive transport. With NaCl Ringer bathing the outer surface of the skin the spontaneous potential was about −30 mV. At this potential the Cl- conductance of the skin was about half of its maximum value. The time course of Cl- current activation following a fast, stepwise change of V from 50 mV to a potential below O mV showed an initial delay of a few seconds, and proceeded with a halftime (T 1/2) which varied as a bell-shaped function of V. The maximum T 1/2 was about 100 s for V = −10 mV in skins exposed to KCl Ringer on the outside. Following adaptation of the toads to a 250 mM-NaCl solution, the fully activated Cl- conductance of the skin was greatly reduced, and the conductance-voltage curve was shifted to the left along the voltage-axis. With NaCl Ringer on the outside the spontaneous potential was about −20 mV, and Cl- conductance activation was possible only outside the physiological range of potentials. The time constant of Cl- conductance activation from closed to fully activated state was more than doubled following salt adaptation of the toads. The active inward Cl- flux disappeared in skins of toads adapted to a 250 mM-NaCl solution, and apparent leakage conductance was reduced. Application of the phosphodiesterase inhibitor 3-isobutyl-1-methyl-xanthine to skin of fully salt-adapted toads increased the transepithelial Cl- conductance, and the time courses of voltage clamp currents became more like those of water-adapted toads. Apparent leakage conductance was increased.(ABSTRACT TRUNCATED AT 400 WORDS)

NaCl adaptation in Rana ridibunda and a comparison with the euryhaline toad Bufo viridis

1975 ◽  
Vol 63 (3) ◽  
pp. 763-773
Author(s):  
U. Katz
Keyword(s):  
Water Uptake ◽  
Sodium Transport ◽  
Tap Water ◽  
Physiological Adaptation ◽  
Salt Adaptation ◽  
Osmotic Gradient ◽  
Rana Ridibunda ◽  
Bufo Viridis ◽  
Water Frogs ◽  
Toad Bufo

The physiological adaptation of the frog Rana ridibunda to saline environment was studied. It was found that blood was always hypertonic to the external solution, but at the highest salinity tolerated (i.e. 300 mOsM) the osmotic gradient across the skin was nearly abolished. Water uptake by the living frog remained unchanged, whereas sodium transport across the skin decreased markedly. Neurohypophyseal hormone increased water uptake and sodium transport to levels similar to those in tap water frogs. Water content of the tissues was not affected by saline adaptation, although it varied appreciably under acute conditions. Oxygen consumption increased in dehydrated frogs, but not in adapted ones. The results are discussed and compared to the euryhaline toad Bufo viridis; the importance of high urea levels for high salt adaptation is stressed.

The Effect of Salt Adaptation and Amiloride on the In Vivo Acid-Base Status of the Euryhaline Toad Bufo Viridis

1981 ◽  
Vol 93 (1) ◽  
pp. 93-99
Author(s):  
U. KATZ
Keyword(s):  
Tap Water ◽  
Salt Adaptation ◽  
Acid Base ◽  
Bufo Viridis ◽  
Acid Base Status ◽  
Simultaneous Decrease ◽  
Toad Bufo

1. The acid-base status of the blood of the toad Bufo viridis was studied during adaptation to high salinity and in tap water containing amiloride. 2. Both salt adaptation and immersion for 2-3 days in 5 x10−4 M amiloride in tap water resulted in a decrease in blood pH (from 7.720 ± 0.026 in tap water to 7.456±0.051 in 500 mOsm NaCl-adapted toads; mean ± S.E.), and a simultaneous decrease in the concentration of HCO3- (from 17.8 ±1.4 in tap water to 9.5±1.2 in salt-adapted toads). 3. In vitro determination of Na+/H+ exchange across the skin showed a 1:1 relation in skins from tap-water-adapted toads; this exchange was inhibited by amiloride. H+ secretion was abolished in skins from salt-adapted toads and the uptake of sodium was reduced.

THE UPTAKE OF TRITIATED LYSINE VASOPRESSIN BY RAT AND PIG PITUITARY NEURAL LOBES IN VITRO

1971 ◽  
Vol 50 (4) ◽  
pp. 669-677 ◽  
Author(s):  
B. A. EDWARDS
Keyword(s):  
Tap Water ◽  
Exchange Chromatography ◽  
Control Group ◽  
Breakdown Product ◽  
Nacl Solution ◽  
Water Control ◽  
Neural Lobe ◽  
Lysine Vasopressin ◽  
And Control

SUMMARY Uptake of tritiated lysine vasopressin ([3H]LVP) was studied in halved neural lobes of rats (which had been given either tap water (control group) or 2% (w/v) NaCl solution as drinking water for 4 days) as well as in slices of pig neural lobe. Uptake of radioactivity into the neural lobes was shown but analysis of the extracts of incubated lobes of both species by ion exchange chromatography showed that very little of it remained in the tissue as hormone. In addition, some radioactivity was associated with trichloroacetic acid-insoluble proteins. After 90 min of incubation, and after correction for the breakdown, the uptake of unchanged [3H]LVP, expressed as a tissue: medium ratio, was 0·14 ± 0·04 and 0·09 ± 0·03 (mean ± s.e.m.) for the saline-treated and control rats respectively, while the tissue: medium ratios for the breakdown product(s) were 6·47 ± 0·45 and 5·50 ± 0·36. The results suggest uptake of [3H]LVP into the cell with almost complete intracellular breakdown of the hormone.

scholarly journals Attraction of Neomegalotomus parvus (Westwood)(Heteroptera: alydidae) to cow urine and ammonia

2010 ◽  
Vol 67 (1) ◽  
pp. 84-86 ◽  
Author(s):  
Jovenil José da Silva ◽  
Iara Cintra de Arruda-Gatti ◽  
Adriana Yatie Mikami ◽  
Aline Pissinati ◽  
Antônio Ricardo Panizzi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Cajanus Cajan ◽  
Tap Water ◽  
Pigeon Pea ◽  
Field Trials ◽  
Nacl Solution ◽  
Cow Urine

The alydid bug parvus (Westwood) is not easily detected in the field and the discovery of attractants may be a suitable way to monitor this species. The attraction of N. parvus to traps (transparent, transparent green and yellow) baited with cow urine and ammonia was studied in two field trials. Traps were placed near a terrace with pigeon pea plants (Cajanus cajan L.). Tap water, NaCl 10% aqueous solution (w/v), cow urine, and ammonia (NH4OH 1% aqueous solution) were tested as attractants in yellow, transparent and transparent green traps. Green traps baited with cow urine caught more bugs than yellow and transparent traps (3.2 and 7.2 times more, respectively), and more bugs than traps of the same color with just water (no captures) or NH4OH solution (14.5 times more). Traps baited with ammonia caught more bugs than traps with water: 14.4, 4.7 and 6.7 times more than transparent green, yellow, and transparent traps, respectively, or NaCl solution: 3.9, 7.6 and 6.2 times, respectively. Both ammonia and cow urine are attractive to N. parvus and may be tested to monitor the bugs in the field.

Chloride transport across the membrane of parotid secretory granules

1990 ◽  
Vol 259 (3) ◽  
pp. C413-C420 ◽  
Author(s):  
K. W. Gasser ◽  
U. Hopfer
Keyword(s):  
Chloride Transport ◽  
Secretory Granules ◽  
Disulfonic Acid ◽  
Parotid Glands ◽  
Transport Pathways ◽  
Anion Selectivity ◽  
Granule Membrane ◽  
Cytoplasmic Side ◽  
Cl Conductance

The Cl- transport pathways in secretory granules isolated from the parotid glands of rats were characterized by the technique of ionophore-induced lysis in defined salt solutions. The granules were shown to possess a Cl- conductance that exhibited a distinct anion selectivity with a sequence I- greater than Br- greater than Cl- greater than F- greater than SO4(2-) much greater than gluconate-. This conductance could be reduced approximately 40% by the stilbene 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS) from the cytoplasmic side; the half-maximal concentration for inhibition was 50 microM. Furthermore, the apparent Cl- conductance was reduced by outwardly directed granule H+ gradients and stimulated by inwardly directed gradients. An outwardly directed H+ gradient mimics the in vivo environment and may serve in a regulatory capacity, providing for a tonic inhibition of transport until the granule fuses with the luminal membrane. The granules also possessed a Cl(-)-HCO3- exchange based on electroneutrality of Cl- uptake and stimulation of this uptake by HCO3-. This pathway displayed a different anion selectivity, I- greater than Br- greater than F- greater than Cl- much greater than SO4(2-) much greater than gluconate-, and was not inhibited by SITS on the cytoplasmic side. The presence of these electrolyte transport pathways in the granule membrane is consistent with the production of primary fluid by parotid acinar cells after fusion of granules with the luminal plasma membrane.

The Use of DEAE Cellulose in the Preparation of a Factor VIII (AHG)-free Bovine Fibrinogen Reagent

1961 ◽  
Vol 6 (02) ◽  
pp. 287-307 ◽  
Author(s):  
W. F Stapp
Keyword(s):  
Factor Viii ◽  
Protein Concentration ◽  
Tap Water ◽  
Deae Cellulose ◽  
Fibrinogen Concentration ◽  
Nacl Solution ◽  
Factor Viii Activity ◽  
Bovine Plasma ◽  
Nacl Concentration ◽  
Optimum Ph

SummaryAdequate fibrinogen reactivity is suggested as an additional requirement for specific fibrinogen reagents, to be added to the well known requirements of protein concentration, optimum pH, and optimum ionic strength. Reasons and a method for testing are outlined.A method for the preparation of a specific fibrinogen reagent, deficient in factor VIII, from BaSO4 adsorbed bovine plasma is described in detail. The method described utilizes either fresh or regenerated DEAE cellulose as an adsorbent in a non-column chromatographic adsorption procedure, associated with a dialysis procedure in which the final fibrinogen product is concentrated and precipitated as a “euglobulin”. The “euglobulin” fibrinogen precipitate was then dissolved/suspended in buffered saline at a specific pH and NaCl concentration. Essentially the method can be briefly outlined into 5 separate steps:1. Dialysis of BaSO4 adsorbed bovine plasma against 0.5% NaCl at pH 6.6 in 0.005 M Imidazole-HCl buffer.2. Washing of DEAE cellulose with the same type of buffered NaCl solution to specific conditions.3. Mixing of the dialyzed BaSO4 adsorbed bovine plasma with the washed DEAE cellulose and separation by centrifugation.4. Concentration of the cellulose adsorbed plasma as a “euglobulin” fibrinogen precipitate by dialysis against running tap water.5. Dissolving of the “euglobulin” fibrinogen precipitate in 0.9% NaCl buffered at pH 6.8.Fibrinogen preparations, prepared with the use of regenerated DEAE cellulose were found to be similar to those prepared by fresh DEAE cellulose in fibrinogen reactivity and deficiency in factor VIII activity, but were found to have less fibrinogen concentration than those prepared using fresh DEAE cellulose.Suggestions were also made for possibly increasing the over-all yield of the fibrinogen reagent through use of a “washing-elution” procedure.The procedure that was used for regenerating the DEAE cellulose was also described in detail and commented upon.

Canine ileal chloride absorption: effect of carbonic anhydrase inhibitor on transport

1964 ◽  
Vol 207 (5) ◽  
pp. 998-1004 ◽  
Author(s):  
Venard R. Kinney ◽  
Charles F. Code
Keyword(s):  
Carbon Dioxide ◽  
Chloride Transport ◽  
Electrical Potential ◽  
Flux Ratio ◽  
Passive Transport ◽  
Carbon Dioxide Content ◽  
Absorption Effect ◽  
A Value ◽  
Chloride Absorption ◽  
Transport Flux

The rates of movement of chloride and water from ileal loops into blood (insorption) and from blood into ileal contents (exsorption) were determined in dogs by the use of radiochloride and deuterium. The transmural electrical potential was measured. The appropriate values then were applied to Ussing's equation. The data indicated that chloride is actively transported by the ileum of the dog. The addition of acetazolamide (Diamox) decreased the observed transport flux ratio of chloride to a value which was similar to the calculated value for passive transport. It was concluded that acetazolamide inhibited active transport of chloride. When acetazolamide was present, the insorption of chloride was decreased while the exsorption of chloride was not affected. Water transport was decreased in parallel with chloride transport. Determinations of carbon dioxide content of the luminal fluid during the tests suggested that the effect of acetazolamide on chloride and water insorption is not related to its carbonic anhydraseinhibiting action.

Interaction of heptanol and pressure on sodium and chloride transport by toad skin

1990 ◽  
Vol 69 (5) ◽  
pp. 1883-1892 ◽  
Author(s):  
M. Li ◽  
S. K. Hong ◽  
J. M. Goldinger ◽  
M. E. Duffey
Keyword(s):  
Channel Blocker ◽  
Chloride Transport ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
Na Transport ◽  
Toad Skin ◽  
Shunt Resistance ◽  
Cl Conductance

We examined the interaction of heptanol and hydrostatic pressure on Na+ and Cl- transport in isolated toad skin. In the presence of Cl-, heptanol decreased short-circuit current (Isc) and total transepithelial resistance (Rt). However, in the absence of Cl- in the mucosal bath, heptanol increased Rt, although it retained the same inhibitory effect on Isc. When transepithelial active Na+ transport was blocked by amiloride, heptanol had no effect on Isc whether or not Cl- was present, whereas it decreased the shunt resistance (Rs) only in the presence of Cl- in the mucosal bath. Moreover, this effect of heptanol on Rs was significantly smaller in the presence of diphenylamine-2-carboxylate (DPC), a known Cl- channel blocker. Pressure also decreased Isc through inhibition of active Na+ transport, but it increased Rs. When heptanol and pressure were applied together, their inhibitory effects on Isc were additive, but their effects on Rs were antagonistic. Furthermore, when a transepithelial Cl- current was produced by reducing the Cl- concentration of the serosal bath, heptanol stimulated this current, which was reversibly inhibited by pressure or DPC addition to the mucosal bath. When the heptanol-stimulated Cl- current was first inhibited by pressure, subsequent DPC addition had less or no effect. These results suggest that one site of an antagonistic interaction of heptanol and pressure in toad skin is an apical membrane Cl- conductance.

Pulsation in Bag Breakup of Round Liquid Jets in Crossflow

2014 ◽  
Vol 1070-1072 ◽  
pp. 1945-1950
Author(s):  
Pei Feng Liu ◽  
Yong Huang ◽  
Zhi Lin Liu ◽  
Lei Sun
Keyword(s):  
Momentum Flux ◽  
High Speed ◽  
Gas Flow ◽  
Tap Water ◽  
Flux Ratio ◽  
Liquid Jets ◽  
High Speed Camera ◽  
Breakup Process ◽  
Test Liquid ◽  
Momentum Flux Ratio

An experiment was conducted to investigate bag breakup process of round liquid jets in crossflow. The objective of this study is to research pulsation law. Specifically, this study measures the onset position of bag, the breakup position of bag, the breakup position of the jet. High-speed camera was used to observe the formation and breakup of bags. The diameter of the nozzle used in the experiment was 0.5mm, 0.8mm, 1mm. The test liquid was tap water. Wea number covers the range of 6~30, and liquid-to-air momentum flux ratio varied from 22 to 211. Present results indicate that in the direction perpendicular to the gas flow, the dimensionless pulsating amount of the onset point of bags (yonset/d) is linear to q, while the dimensionless pulsating amount of breakup point of bags (ybag/d) and the dimensionless pulsating amount of breakup point of the jet (yjet/d) is linear to ln (q). The dimensionless pulsating amount of these points in the direction of gas flow is irregular.

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