Relevance of sodium transport pool measurements in toad bladder tissue for the elucidation of the mechanism whereby hormones stimulate active sodium transport

1969 ◽  
Vol 313 (3) ◽  
pp. 197-221 ◽  
Author(s):  
Jean Crabbé ◽  
Paul de Weer
Keyword(s):  
Sodium Transport ◽  
Toad Bladder ◽  
Active Sodium ◽  
Bladder Tissue ◽  
Active Sodium Transport

scholarly journals The Electrical Characteristics of Active Sodium Transport in the Toad Bladder

1963 ◽  
Vol 46 (3) ◽  
pp. 491-503 ◽  
Author(s):  
Howard S. Frazier ◽  
Alexander Leaf
Keyword(s):  
Sodium Transport ◽  
Short Circuit ◽  
Diffusion Potential ◽  
Toad Bladder ◽  
Chloride Diffusion ◽  
Active Sodium ◽  
High Potassium ◽  
Potential Step ◽  
Active Sodium Transport ◽  
Wide Range

The mechanism responsible for active sodium transport in the urinary bladder of the toad appears to be located at the serosal boundary of the epithelial cell layer of the bladder. Studies of the potential step observed at the serosal boundary in the open-circuited state were undertaken in an attempt to define the factors responsible for its production. Glass micropipettes were used to measure the serosal potential step in bladders exposed on the serosal side to solutions of high potassium or of high potassium and low chloride concentration. Observed potentials exceed the maximum values which would have been expected if the serosal potential step were a potassium or chloride diffusion potential. Measurements of net cation flux exclude the possibility of a diffusion potential at this border due to the passive movement of any anionic species. The observed independence of transbladder potential and short-circuit current from the pH of the serosal medium over a wide range of pH makes it unlikely that the observed serosal potential step is a hydrogen ion diffusion potential. We conclude that the active sodium transport mechanism in toad bladder is "electrogenic."

scholarly journals THE EFFECT OF CALCIUM WITHDRAWAL ON THE STRUCTURE AND FUNCTION OF THE TOAD BLADDER

1965 ◽  
Vol 25 (3) ◽  
pp. 195-209 ◽  
Author(s):  
Richard M. Hays ◽  
Bayla Singer ◽  
Sasha Malamed
Keyword(s):  
Epithelial Cells ◽  
Sodium Transport ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Structure And Function ◽  
Toad Bladder ◽  
Active Sodium ◽  
Bathing Medium ◽  
Active Sodium Transport ◽  
And Function

Previous reports have indicated that calcium is necessary to support active sodium transport by the toad bladder, and may be required as well in the action of vasopressin on both toad bladder and frog skin. The structure and function of the toad bladder has been studied in the absence of calcium, and a reinterpretation of the previous findings now appears possible. When calcium is withdrawn from the bathing medium, epithelial cells detach from one another and eventually from their supporting tissue. The short-circuit current (the conventional means of determining active sodium transport) falls to zero, and vasopressin fails to exert its usual effect on short-circuit current and water permeability. However, employing an indirect method for the estimation of sodium transport (oxygen consumption), it is possible to show that vasopressin exerts its usual effect on Qoo2 when sodium is present in the bathing medium. Hence, it appears that the epithelial cells maintain active sodium transport when calcium is rigorously excluded from the bathing medium, and continue to respond to vasopressin. The failure of conventional techniques to show this can be attributed to the structural alterations in the epithelial layer in the absence of calcium. These findings may provide a model for the physiologic action of calcium in epithelia such as the renal tubule.

Role of the inhibitory effect of tetrodotoxin on the active sodium transport of the toad bladder

1968 ◽  
Vol 303 (1) ◽  
pp. 49-54 ◽  
Author(s):  
F. Marumo ◽  
T. Yamada ◽  
Y. Asano ◽  
T. Sasaoka ◽  
A. Yoshida ◽  
...  
Keyword(s):  
Sodium Transport ◽  
Inhibitory Effect ◽  
Toad Bladder ◽  
Active Sodium ◽  
Active Sodium Transport

scholarly journals Respiration and Active Sodium Transport of Isolated Toad Bladder

1959 ◽  
Vol 234 (6) ◽  
pp. 1625-1629
Author(s):  
Alexander Leaf ◽  
Lot B. Page ◽  
John Anderson ◽  
Dorothy B. Richardson
Keyword(s):  
Sodium Transport ◽  
Toad Bladder ◽  
Active Sodium ◽  
Active Sodium Transport

DECREASED EFFECTIVENESS OF ALDOSTERONE ON ACTIVE SODIUM TRANSPORT BY THE ISOLATED TOAD BLADDER IN THE PRESENCE OF OTHER STEROIDS

1964 ◽  
Vol 47 (3) ◽  
pp. 419-432 ◽  
Author(s):  
Jean Crabbé
Keyword(s):  
Active Transport ◽  
Sodium Transport ◽  
Concentration Ratio ◽  
Effective Concentration ◽  
Toad Bladder ◽  
Active Sodium ◽  
Active Sodium Transport ◽  
Hormonal Effect ◽  
Serosal Surface

ABSTRACT Aldosterone can stimulate the active transport of sodium by the isolated toad bladder in vitro. Corticosterone, cortisol, 17β-oestradiol and progesterone had no such effect despite incubation of the preparation with more than 100 times the smallest effective concentration of aldosterone. When the serosal surface of the membranes was exposed to 10 μg% d-aldosterone combined with 100 times this concentration of corticosterone, cortisol or progesterone, the stimulating action of aldosterone was reduced. Spirolactone SC 9420 failed to exert by itself a significant effect on the isolated toad bladder in vitro, but this compound blocked the stimulation by aldosterone of active sodium transport in vitro when present at concentrations 50 times those of aldosterone. When the concentration ratio was 10:1, a hormonal effect could be demonstrated, except at the highest concentration of the drug used.

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