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

Hays, Richard M.; Leaf, Alexander

doi:10.1085/jgp.45.5.905

Cited by 251 publications

(103 citation statements)

References 20 publications

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“…It has been known for some time that this hormone exerts a stimulatory effect on sodium transport in both frog skin (Ussing and Zerahn, 1951) and toad bladder (Leaf et al, 1958), as well as in other epithelial structures. In addition, the hormone increases the passive permeability of these tissues to water (Koefoed-Johnsen and Ussing, 1953;Hays and Leaf, 1962). In the latter case, it has been shown clearly that the site of action of the hormone is on the mucosal side of the cells (MacRobbie and Ussing, 1961;Peachey and Rasmussen, 1961), although it must be added to the serosal medium to have any effect.…”

Section: Discussionmentioning

confidence: 99%

The Kinetics of Sodium Transport in the Toad Bladder

Finn

1971

The Journal of General Physiology

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In the accompanying paper, a compartmental model for the toad bladder sodium transport system was developed. In the present paper, the model is tested by determining the effects of antidiuretic hormone on the pools and fluxes. It is shown that this hormone affects only that sodium pool previously designated as the transport pool, and that the effects are on two separate sites. In the first place, the hormone stimulates entry at the mucosal side of the transport compartment, and by this means brings about an increase in the amount of sodium contained in the compartment. Second, the hormone has a distinct stimulatory effect on the rate coefficient for efflux across the serosal boundary, the pump rate coefficient. Evidence is presented that under control conditions, the pump rate coefficient is a decreasing function of the pool size, a characteristic feature of a saturating system. Therefore, the effect of vasopressin in increasing both the pool size and the pump rate coefficient must be construed as a direct effect on the pump, and not one which is secondary to the increase in the pool size. Furthermore, it is shown that the effect of the hormone on the sodium pump is not dependent on the presence of sodium in the serosal medium.In the accompanying paper (Finn and Rockoff, 1971) it was shown that it is possible to represent toad bladder sodium content by a compartmental model. It was found that a system containing two noncommunicating tissue compartments satisfied the data obtained from the washout of radioactive sodium, and that one of these compartments was quite likely to be the transport pool. However, in order to establish more firmly that such a model is biologically relevant, it is necessary to demonstrate that biological perturbations affect the system in a consistent and reasonable manner. In the present paper, we explore the effects of antidiuretic hormone on these transport parameters. In addition, some of the effects of changes in the sodium concentration in the media will be examined.

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Section: Discussionmentioning

confidence: 99%

The Kinetics of Sodium Transport in the Toad Bladder

Finn

1971

The Journal of General Physiology

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“…The water permeability response of the toad urinary bladder is rather specific in that only three types of compounds have to date been found capable of eliciting this effect reversibly: neurohypophyseal hormones (9,23,41), methylxanthines, and cyclic AMP (33). There is considerable evidence that cyclic AMP is involved in the mediation of the action of neurohypophyseal hormones as well as of theophylline (32).…”

Section: Discussionmentioning

confidence: 99%

Threshold and Receptor Reserve in the Action of Neurohypophyseal Peptides

Eggena

Schwartz

Walter

1970

The Journal of General Physiology

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The interrelationship of several physiological receptors which influence the hydroosmotic response of the toad urinary bladder was studied employing neurohypophyseal peptides, prostaglandin E 1 , theophylline, and cyclic nucleotides. The binding property of agonists (pD 2 ), synergists (pS 2 ), competitive antagonists (pA 2 ), and noncompetitive antagonists (pD 2 ') was determined after a suitable methodology had been developed. A series of neurohypophyseal peptides was examined in detail for their catalytic activity. It was found that the replacement of the hydroxy radical of the tyrosine residue in oxytocin by a methoxy and then by an ethoxy radical led to a progressive decline in the catalytic activity of the hormone-corresponding to a change from agonist to partial agonist to competitive antagonist. [4-Leucine]-mesotocin behaved as a competitive antagonist of oxytocin. Prostaglandin E 1 (PGE 1 ) was found to be a noncompetitive inhibitor of neurohypophyseal peptides and theophylline; whereas the maximal hydroosmotic response of the bladder to [2-0-methyltyrosine]-oxytocin and theophylline was greatly depressed by PGE 1 , the response to saturating concentrations of oxytocin was only slightly diminisheda finding which reveals a "receptor reserve" for oxytocin. Saturating concentrations of [2-0-ethyltyrosine]-oxytocin, inactive per se, potentiate theophylline-disclosing a "threshold phenomenon" for the mediation of neurohypophyseal hormone action. It is concluded that neurohypophyseal peptides are capable of producing graded effects on adenyl cyclase both below and above the range of enzyme activity which evokes graded changes in membrane permeability.

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“…In addition, indirect information concerning the characteristics of the DCT has been obtained from clearance (20)(21)(22)(23)(24)(25)(26) and from toad bladder experiments (27)(28)(29)(30). However, the recent observations of Woodhall and Tisher raise serious questions about the interpretation of previous micropuncture studies in relation to functional characterization of the DCT (31).…”

Section: Introductionmentioning

confidence: 99%

A functional comparison of the cortical collecting tubule and the distal convoluted tubule.

Gross¹,

Imai²,

Kokko³

1975

J. Clin. Invest.

167

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AB STRA CT Electrical and permeability features of the distal convoluted tubule (DCT) and the cortical collecting tubule (CCT) were examined using the technique in which isolated segments of rabbit tubules were perfused in vitro. When rabbits were given a regular diet and tubules were perfused and bathed in artificial solutions simulating plasma ultrafiltrate, the potential difference (PD) was + 3.7+1.9 mV in the CCT and -40.4±2.8 mV in the DCT. When rabbits were given a low sodium, high potassium diet plus i.m. deoxycorticosterone acetate (DOCA) (1 mg/kg per day), the PD in both the CCT (-30.8±3.9 mV) and the DCT (-33.8±5.5 mV) was negative. The PD in the CCT was quantitatively similar to that of diet plus DOCA when animals were given DOCA alone. The PD in both segments was inhibited by ouabain (10' M) in the bath or by amiloride (10' M) in the perfusate. Addition of vasopressin (200 AU/ml) to the bath caused a gradual decline of PD to zero in the CCT but failed to produce a potential response in the DCT. Osmotic water permeability was essentially zero in both segments in the absence of vasopressin. After addition of the vasopressin to the bath, osmotic water permeability in the DCT remained zero but increased to 71.9+25.5 x 10-7 cm/s per atm in the CCT. We conclude that both segments are similar in that each possesses an electrogenic transport process but that these segments differ in that: (a) the CCT requires either exogenous or endogenous mineralocorticoid to maintain a maximal negative PD, whereas the PD in the DCT appears to be independent of mineralocorticoid effect; and (b) the CCT responds to vasopressin with a marked rise in water permeability, whereas the DCT is impermeable to water before and after addition of vasopressin.Dr. Imai's present address is the Department of Pharmacology, Jichi Medical School, Tochigi, Japan 329-04.

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

Cited by 251 publications

References 20 publications

The Kinetics of Sodium Transport in the Toad Bladder

The Kinetics of Sodium Transport in the Toad Bladder

Threshold and Receptor Reserve in the Action of Neurohypophyseal Peptides

A functional comparison of the cortical collecting tubule and the distal convoluted tubule.

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