scholarly journals Water Transfer by The Toad Bladder

2000 ◽  
Vol 1 (1) ◽  
pp. 10-14
Author(s):  
Sulaiman Ibrahim
Keyword(s):  
Water Movement ◽  
Water Transfer ◽  
Toad Bladder ◽  
Bathing Solution ◽  
Osmotic Gradient ◽  
Serosal Surface ◽  
Time Period ◽  
Initial Control ◽  
Solution Bathing ◽  
Toad Bufo

ABSTRACT. Studies have been made on the isolated urinary bladder of the toad, Bufo marinus, in an attempt to investigate the effect of vasopressin on the permeability of water from mucosal surface to serosal surface of the toad bladder. The method adapted was that described by Bentley ( 1 ). The bilobed bladder of the toad is devided into two separate sacs. Each of the sacs is filled with a dilute Ringers solution and then immersed in aerated isotonic Ringers solution. The rate of water loss along the imposed osmotic gradient is estimated by weighing the sacs in air at 30 minute intervals and nothing the weight  loss in that time period. In most studies one bladder sac serves as a control for the contra lateral experimental obtained from the same animal. Osmotic flow of water is negligible in both sacs during the initial control periods. However, the addition of vasopressin to the solution bathing the serosal surface of the membrane result in a market increase in net water movement. The effect is readily reversed by rinsing the bladder and adding hormone free Ringgers solution to the serosal surface. Characteristically no response is elicited by addition of hormone to the mucosal bathing solution.

THE EFFECT OF THYROID HORMONES ON WATER PERMEABILITY OF THE ISOLATED BLADDER OF THE TOAD BUFO BUFO

1964 ◽  
Vol 28 (2) ◽  
pp. 205-211 ◽  
Author(s):  
K. GREEN ◽  
A. J. MATTY
Keyword(s):  
Oxygen Uptake ◽  
Sodium Transport ◽  
Driving Force ◽  
Water Movement ◽  
Bufo Bufo ◽  
Toad Bladder ◽  
Osmotic Gradient ◽  
Serosal Surface ◽  
Toad Bufo ◽  
Toad Bufo Bufo

SUMMARY Thyroxine at 10−6m concentration enhances water movement from the mucosal to the serosal surface of the isolated toad bladder in the absence of an osmotic gradient. It is suggested that this is caused by the effect of thyroxine on sodium transport which creates a driving force for the increased water movement. Thyroxine caused this effect when applied on either side of the membrane, but was more effective when applied to the serosal surface. Incubation of different bladders successively in the same triiodothyronine solution indicated that triiodothyronine may be rapidly utilized. A mixture of thyroxine and triiodothyronine caused a diphasic effect on water loss down an osmotic gradient. The analogues tetraiodothyroproprionic acid and tetraiodothyroformic acid had no effect on water movement down an osmotic gradient across the isolated toad bladder nor did they affect oxygen uptake or sodium transport. The results support the concept that thyroxine and triiodothyronine act on permeability processes in and across cell membranes.

DIRECTIONAL DIFFERENCES IN THE PERMEABILITY TO WATER OF THE ISOLATED URINARY BLADDER OF THE TOAD, BUFO MARINUS

1961 ◽  
Vol 22 (1) ◽  
pp. 95-100 ◽  
Author(s):  
P. J. BENTLEY
Keyword(s):  
Urinary Bladder ◽  
Electric Current ◽  
Opposite Direction ◽  
Water Movement ◽  
Water Transfer ◽  
Bufo Marinus ◽  
Osmotic Gradient ◽  
Serosal Side ◽  
Toad Bufo

SUMMARY 1. If the osmotic gradient is favourable vasopressin increases the rate of water movement across the bladder of the toad from the serosal to the epithelial side, which is the opposite direction to that seen physiologically. 2. Water transfer down an osmotic gradient is 1·8 times more rapid towards the serosal than towards the epithelial side. Vasopressin increases this difference so that water is moving 4·9 times as rapidly to the serosal side. Iodoacetate reduces this effect of vasopressin. 3. If water is moving down an osmotic gradient towards the anode, a higher electric current increases the water movement in the presence, but not in the absence, of vasopressin. If water movement is taking place towards the cathode an increased current has no effect. 4. With vasopressin present, absence of sodium on the epithelial side of the bladder reduces water transfer down an osmotic gradient towards the serosal side, but has no effect on water movement down an osmotic gradient in the opposite direction.

PERMEABILITY AND RESPIRATION EFFECTS OF THYROIDAL HORMONES ON THE ISOLATED BLADDER OF THE TOAD BUFO BUFO

1963 ◽  
Vol 25 (4) ◽  
pp. 411-425 ◽  
Author(s):  
A. J. MATTY ◽  
K. GREEN
Keyword(s):  
Oxygen Uptake ◽  
Water Loss ◽  
Enzyme Inhibitors ◽  
Water Movement ◽  
Bufo Bufo ◽  
Metabolic Energy ◽  
Toad Bladder ◽  
Osmotic Gradient ◽  
Close Relationship ◽  
Toad Bufo

SUMMARY l-Thyroxine and 3,5,3′-triiodo-l-thyronine in concentrations of 10−8 m to 10−5 m were shown to increase the oxygen uptake and water transfer down an osmotic gradient in the isolated urinary bladder of Bufo bufo. The increase in water transport after treatment with thyroxine and triiodothyronine was related linearly to the log dose. The increase in O2 uptake and water movement in equimolar concentrations of thyroxine and triiodothyronine were similar but the responses to the latter were more rapid. Substitution of sodium ions by choline in the incubation medium resulted in a fall of oxygen uptake by the bladder, and a slight lowering of water loss. When thyroxine was added, oxygen uptake increased to the same extent in both media but only in sodium saline did water loss increase greatly. Specific enzyme inhibitors prevented the thyroxine-induced increase in water loss across the isolated toad bladder, indicating that metabolic energy is necessary for this alteration in permeability. Triiodothyronine and thyroxine caused an increased water loss across the isolated toad bladder when placed on either the mucosal or serosal surface. Two analogues of the thyroid hormones, 3,5,3′-triiodothyroacetic acid and 3,5,3′,5-tetraiodothyroacetic acid, caused an extremely rapid, but transient, movement of water across the bladder; their action and that of triiodothyronine and thyroxine is compared. An hypothesis is proposed tentatively to account for the mode of action of thyroxine on the permeability of the isolated toad bladder, taking into account the close relationship between increases in water permeability and metabolism, particularly that involving sodium transport.

OSMOTIC INHIBITION OF THE NATRIFERIC RESPONSE OF THE TOAD URINARY BLADDER TO VASOPRESSIN

1975 ◽  
Vol 67 (1) ◽  
pp. 119-125
Author(s):  
P. J. BENTLEY
Keyword(s):  
Urinary Bladder ◽  
Water Movement ◽  
Short Circuit ◽  
Electrical Potential ◽  
Short Circuit Current ◽  
Toad Bladder ◽  
Toad Urinary Bladder ◽  
Electrical Potential Difference ◽  
Osmotic Gradient

SUMMARY The electrical potential difference and short-circuit current (scc, reflecting active transmural sodium transport) across the toad urinary bladder in vitro was unaffected by the presence of hypo-osmotic solutions bathing the mucosal (urinary) surface, providing that the transmural flow of water was small. Vasopressin increased the scc across the toad bladder (the natriferic response), but this stimulation was considerably reduced in the presence of a hypo-osmotic solution on the mucosal side, conditions under which water transfer across the membrane was also increased. This inhibition of the natriferic response did not depend on the direction of the water movement, for if the osmotic gradient was the opposite way to that which normally occurs, the response to vasopressin was still reduced. The natriferic response to cyclic AMP was also inhibited in the presence of an osmotic gradient. Aldosterone increased the scc and Na+ transport across the toad bladder but this response was not changed when an osmotic gradient was present. The physiological implications of these observations and the possible mechanisms involved are discussed.

THE EFFECTS OF NEUROHYPOPHYSIAL EXTRACTS ON WATER TRANSFER ACROSS THE WALL OF THE ISOLATED URINARY BLADDER OF THE TOAD BUFO MARINUS

1958 ◽  
Vol 17 (3) ◽  
pp. 201-209 ◽  
Author(s):  
P. J. BENTLEY
Keyword(s):  
Urinary Bladder ◽  
Bladder Wall ◽  
Water Transfer ◽  
Passive Movement ◽  
Bufo Marinus ◽  
Metabolic Inhibitors ◽  
Osmotic Gradient ◽  
High Concentrations ◽  
Toad Bufo

SUMMARY 1. An in vitro preparation of the urinary bladder of Bufo marinus is described. 2. Small doses of 'Pituitrin' markedly increase the rate of water transfer across the bladder wall when the solutions inside the bladder are hypotonic. 3. Passive movement is small and increases slightly with increases in the osmotic gradient across the bladder wall. It is unaffected by changes in substrate levels or any of the metabolic inhibitors tested except for cyanide which increases it in some cases. 4. The vasopressor neurohypophysial fraction is more active than the oxytocic one in increasing water transfer across the bladder wall. 5. The increase in water transfer depends on an intact oxygen supply and sufficient glucose or pyruvate. 6. Iodoacetate, malonate, cyanide, 2–4-dinitrophenol, and bubbling 5% CO2+95% O2 through Ringer's solution inhibit the water transfer in response to neurohypophysial extract. 7. Diamox is only an effective inhibitor at very high concentrations. 8. The possible mechanism of the water transfer is discussed.

scholarly journals Studies on the Movement of Water through the Isolated Toad Bladder and Its Modification by Vasopressin

1962 ◽  
Vol 45 (5) ◽  
pp. 905-919 ◽  
Author(s):  
Richard M. Hays ◽  
Alexander Leaf
Keyword(s):  
Water Movement ◽  
Bladder Wall ◽  
Mucosal Surface ◽  
Diffusion Permeability ◽  
Osmotic Gradient ◽  
Unidirectional Flux ◽  
Neurohypophyseal Hormone ◽  
Toad Bufo ◽  
Net Fluxes ◽  
Net Transfer

Measurements of diffusion permeability and of net transfer of water have been made across the isolated urinary bladder of the toad, Bufo marinus, and the effects thereon of mammalian neurohypophyseal hormone have been examined. In the absence of a transmembrane osmotic gradient, vasopressin increases the unidirectional flux of water from a mean of 340 to a mean of 570 µl per cm2 per hour but the net water movement remains essentially zero. In the presence of an osmotic gradient but without hormone net transfer of water remains very small. On addition of hormone large net fluxes of water occur; the magnitude of which is linearly proportional to the osmotic gradient. The action of the hormone on movement of water is not dependent on the presence of sodium or on active transport of sodium. Comparison of the net transport of water and of unidirectional diffusion permeability of the membrane to water indicates that non-diffusional transport must predominate as the means by which net movement occurs in the presence of an osmotic gradient. An action of the hormone on the mucosal surface of the bladder wall is demonstrated. The effects of the hormone on water movement are most simply explained as an action to increase the permeability and porosity of the mucosal surface of the membrane.

THE EFFECT OF VALINOMYCIN ON THE TOAD BLADDER: ANTAGONISM TO VASOPRESSIN AND ALDOSTERONE

1969 ◽  
Vol 45 (2) ◽  
pp. 287-295 ◽  
Author(s):  
P. J. BENTLEY
Keyword(s):  
Macrolide Antibiotic ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Water Transfer ◽  
Toad Bladder ◽  
Na Transport ◽  
Bathing Medium ◽  
Sodium Transfer ◽  
Sites Of Action ◽  
Subsequent Addition

SUMMARY The macrolide antibiotic valinomycin decreased short-circuit current (SCC, Na transport) across the isolated bladder of the toad. This effect was not overcome by increasing the K+ levels in the bathing medium or by the action of amphotericin B. The effects of vasopressin on both sodium and water transfer across the toad bladder were inhibited by valinomycin and the latter inhibition is non-competitive. The action of theophylline in increasing water transfer across the bladder was also inhibited. Cyclic AMP also increased water and Na+ transfer across the bladder but its action was not reduced by the macrolide. These results suggest that valinomycin inhibits adenyl cyclase. Aldosterone increases sodium transport across the toad bladder and this action was abolished by previous incubation of the tissue with the macrolide. Once the steroid-induced effect had been established subsequent addition of valinomycin did not alter the sodium transfer. Valinomycin thus appears to have several sites of action on the toad bladder.

Further Observations on the Physiology of Salinity Adaptation in the Crab-Eating Frog (Rana Cancrivora)

1968 ◽  
Vol 49 (1) ◽  
pp. 185-193
Author(s):  
MALCOLM S. GORDON ◽  
VANCE A. TUCKER
Keyword(s):  
Sea Water ◽  
Short Circuit ◽  
Electrical Potential ◽  
Short Circuit Current ◽  
Ringer Solution ◽  
Osmotic Concentration ◽  
Green Toad ◽  
The Face ◽  
Solution Bathing ◽  
Toad Bufo

1. Total rates of urea loss from adult euryhaline crab-eating frogs (Rana cancrivora) adapted to various environmental salinities between fresh water and 80 % sea water increase as salinity increases above 40% sea water. Oxygen consumption is constant in rate in all salinities studied. 2. The presence of urea in the Ringer solution bathing isolated pieces of skin of frogs adapted to 60% sea water increases both the electrical potential and the inwardly directed short-circuit current across the skin. 3. In skeletal muscle cells addition of intracellular solutes maintains tissue hydration in the face of large increases in plasma osmotic concentration in high-salinity media. Changes in the intracellular urea and free amino acid concentrations are primarily responsible for increases in intracellular osmotic concentration. 4. Some implications of these observations are discussed and comparisons made with the euryhaline green toad, Bufo viridis.

Effect of temperature on transcapillary water movement in isolated cat hindlimb

1985 ◽  
Vol 249 (4) ◽  
pp. H792-H798
Author(s):  
M. B. Wolf ◽  
P. D. Watson
Keyword(s):  
Low Temperature ◽  
Water Movement ◽  
Control Period ◽  
Ambient Air ◽  
Tissue Temperature ◽  
Thigh Muscle ◽  
Effect Of Temperature ◽  
Air Temperatures ◽  
Initial Control ◽  
Water Viscosity

Capillary filtration coefficient (CFC) was measured in the isolated cat hindlimb preparation, perfused at 20 ml X min-1 X 100 g muscle-1 with a perfusate containing 6 g/dl albumin and normal electrolyte concentrations, to which were added 50 ml of the cat's blood and 6 micrograms of the vasodilator isoproterenol. CFC was determined three to six times in an initial control period during which the tissue temperature (measured by a 5-mm disk thermistor implanted in a thigh muscle) was controlled near 37 degrees C. Tissue temperature was decreased to 5-10 degrees C by lowering perfusate and ambient air temperatures. About 50 min were required for tissue temperature equilibration. CFC was measured at low temperature and then again at 37 degrees C. For nine experiments, the ratio of CFC at low temperature to that in the 37 degrees C control periods averaged 87% of the ratio of water viscosity at 37 degrees C to that at low temperature. The activation energy for water calculated from these data was 5.0 kcal/mol. These results may be explained by all transcapillary water flow moving by diffusion through narrow pores or by about 90% moving by convection, with the remainder going through a lipid pathway. However, the results may be entirely due to a direct effect of temperature on the geometry of the transcapillary pathway for water movement.

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