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.

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.

THE EFFECTS OF IONIC CHANGES ON WATER TRANSFER ACROSS THE ISOLATED URINARY BLADDER OF THE TOAD BUFO MARINUS

1959 ◽  
Vol 18 (4) ◽  
pp. 327-333 ◽  
Author(s):  
P. J. BENTLEY
Keyword(s):  
Urinary Bladder ◽  
Potassium Concentration ◽  
Choline Chloride ◽  
Bladder Wall ◽  
Water Transfer ◽  
Bufo Marinus ◽  
Serosal Side ◽  
Ionic Changes ◽  
Toad Bufo

SUMMARY 1. The effects of ionic changes in the bath fluids on water transfer across an in vitro preparation of the urinary bladder of the toad Bufo marinus were investigated. 2. Calcium was necessary to maintain the normal low permeability of the bladder to water in the absence of Pituitrin. Magnesium, strontium and manganese but not barium could substitute for calcium. 3. With low concentration of calcium there was a reduction in the water transfer across the bladder wall in response to Pituitrin and no other divalent ion could substitute for calcium. 4. Exclusion of potassium from the serosal side of the bladder reduced the water transfer in the presence of Pituitrin. Increase in potassium concentration above normal levels also inhibited the response to hormone. When no Pituitrin was present there was no change in water loss from the bladder with alterations in potassium concentration. Absence of potassium from the epithelial side of the bladder had no effect whether Pituitrin was present or not. 5. The presence of sodium on the epithelial side increased the water transfer in response to Pituitrin and neither lithium, choline nor potassium could substitute for it. Replacement of 50% of the sodium chloride on the serosal side of the bladder by choline chloride decreased the water transfer in response to Pituitrin.

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.

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.

Active phosphate transport across the urinary bladder of the toad,Bufo marinus

1977 ◽  
Vol 32 (1) ◽  
pp. 291-299 ◽  
Author(s):  
Billy B. Sellers ◽  
Julia A. Hall ◽  
Carol W. Both ◽  
Stanley A. Mendoza
Keyword(s):  
Urinary Bladder ◽  
Phosphate Transport ◽  
Bufo Marinus ◽  
Toad Bufo

REGULATION OF THE PERMEABILITY TO WATER IN TOAD URINARY BLADDER: THE EFFECT OF COPPER

1972 ◽  
Vol 55 (1) ◽  
pp. 1-9 ◽  
Author(s):  
MARIO PARISI ◽  
ZULEMA F. PICCINNI
Keyword(s):  
Urinary Bladder ◽  
Cyclic Amp ◽  
Water Movement ◽  
Inhibitory Effect ◽  
Toad Urinary Bladder ◽  
Serosal Side ◽  
Effect Of Copper

SUMMARY The effect of Cu2+ in concentrations from 1 × 10−7 to 1 × 10−4 mol/1 on water movement across the toad urinary bladder in vitro was studied. Although Cu2+ did not alter the permeability to water by itself, it strongly inhibited the hydrosmotic response induced by oxytocin and theophylline. This effect was present only when the ion was added to the serosal side. The observed inhibition was not completely reversible even at the lower Cu2+ concentrations. No interaction of Cu2+ with cyclic AMP was observed. However, a reversible inhibitory effect of the ion on the hydrosmotic response induced by increasing tonicity of the medium was demonstrated. In this case Cu2+ was effective from both sides. It is concluded that Cu2+ has two effects: (1) a non-reversible action on the cyclase system, inhibiting the responses to oxytocin and theophylline; (2) a reversible action on the 'osmosensitive mechanism', inhibiting the response induced by increasing tonicity.

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.

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