Effect of osmotic gradient on ADH-induced intramembranous particle aggregates in toad bladder

1980 ◽  
Vol 52 (2) ◽  
pp. 181-184 ◽  
Author(s):  
Stephen J. Ellis ◽  
William A. Kachadorian ◽  
Vincent A. DiScala
Keyword(s):  
Toad Bladder ◽  
Osmotic Gradient ◽  
Intramembranous Particle ◽  
Particle Aggregates ◽  
Intramembranous Particle Aggregates

Possible roles for microtubules and microfilaments in ADH action on toad urinary bladder

1979 ◽  
Vol 236 (1) ◽  
pp. F14-F20 ◽  
Author(s):  
W. A. Kachadorian ◽  
S. J. Ellis ◽  
J. Muller
Keyword(s):  
Water Flow ◽  
Cytochalasin B ◽  
Toad Urinary Bladder ◽  
Intramembranous Particle ◽  
Luminal Membrane ◽  
Osmotic Water ◽  
Particle Aggregates ◽  
Aggregation Phenomenon ◽  
Osmotic Water Flow ◽  
Intramembranous Particle Aggregates

Intramembranous particle aggregates in the luminal membrane of toad bladder granular cells after vasopressin stimulation have been found to correlate closely and specifically with induced alterations of water permeability. Roles for microtubules and microfilaments in mediating the latter response have been proposed on the basis of studies involving colchicine and cytochalasin B, respectively. In the present investigation the effects of these agents on both initiating and sustaining vasopressin-induced osmotic water flow and the particle aggregation phenomenon were studied. The results indicate that during initiation the aggregation and water flow responses to vasopressin are each colchicine- and cytochalasin B-sensitive and that these sensitivities can be wholly additive. However, after full vasopressin stimulation is established, the same responses demonstrate sensitivity only to cytochalasin B, not to colchicine. The findings, therefore, suggest that microtubules and microfilaments may be independently necessary for the initiation of the aggregation and water flow responses to vasopressin, and that microfilaments, but not microtubules, are required for their maintenance.

Effects of cellular acidification on ADH-induced intramembrane particle aggregates

1984 ◽  
Vol 246 (1) ◽  
pp. C157-C159 ◽  
Author(s):  
M. Parisi ◽  
J. Bourguet
Keyword(s):  
Membrane Surface ◽  
Water Flux ◽  
Medium Ph ◽  
Intramembranous Particle ◽  
Intramembrane Particle ◽  
Cyclic Monophosphate ◽  
Particle Aggregates ◽  
Camp Levels ◽  
Cellular Acidification ◽  
Intramembranous Particle Aggregates

8-Bromoadenosine 3',5'-cyclic monophosphate [an analogue of adenosine 3',5'-cyclic monophosphate (cAMP), the intracellular mediator for antidiuretic hormone (ADH) action] induces, in frog urinary bladder, an increase in water permeability that is rapidly and reversibly inhibited by cellular acidification. The effect of CO2 bubbling on the simultaneously observed intramembranous particle aggregates, which probably represent water channels, depended on the time that elapsed after changing medium pH: 3 min of CO2 bubbling depressed the water flux by 70%, whereas the membrane surface occupied by the aggregates remained unchanged. On the contrary, after 9-15 min of CO2 bubbling, both the water flux and the surface area occupied by the aggregates were strongly reduced. These results can be interpreted by accepting two post-cAMP levels of action for cellular acidification: 1) the channels themselves that, as previously suggested by ADH experiments at low temperature, would shift their structure from an "open" to a "closed" state, and 2) the mechanism that controlled the aggregates' plug in and removal.

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.

Particle aggregates in plasma and intracellular membranes of toad bladder (granular cell)

1977 ◽  
Vol 33 (10) ◽  
pp. 1364-1367 ◽  
Author(s):  
Fabienne Humbert ◽  
R. Montesano ◽  
Alda Grosso ◽  
R. C. de Sousa ◽  
L. Orci
Keyword(s):  
Granular Cell ◽  
Toad Bladder ◽  
Intracellular Membranes ◽  
Particle Aggregates

Antidiuretic hormone moves membranes

1988 ◽  
Vol 255 (3) ◽  
pp. F375-F382 ◽  
Author(s):  
J. S. Handler
Keyword(s):  
Plasma Membrane ◽  
Antidiuretic Hormone ◽  
Water Permeability ◽  
Apical Membrane ◽  
Collecting Duct ◽  
Toad Bladder ◽  
Cell Swelling ◽  
Apical Plasma Membrane ◽  
Principal Cells ◽  
Particle Aggregates

This review focuses on events at the apical plasma membrane of toad urinary bladder and mammalian collecting duct as their permeability to water changes in response to antidiuretic hormone (ADH) and to its withdrawal. The major marker of the permeability change is observed in freeze-fracture electron microscopy of the apical plasma membrane and consists of a dramatic increase in membrane particle aggregates and, in toad bladder but not in collecting duct, in fused vesicles (aggrephores) that contain particle aggregates in their limiting membranes. Withdrawal of ADH is accompanied by endocytosis at the apical membrane, reflecting retrieval of water-permeable, particle aggregate-containing membrane. Covalent labeling of the external surface of the apical membrane of toad bladder identifies specific proteins that are present in the apical membrane only during the response to ADH. Proteins of the same molecular weights are also present in the retrieved membrane when ADH is withdrawn. Several controversial areas are considered, including the extent of cell swelling as water flows across the epithelium from dilute apical solution to isotonic basal solution, whether only principal cells or principal cells and intercalated cells participate in the water permeability response of the collecting duct, the role of the cytoskeleton in the water permeability response, and the proposed second water permeability barrier that is affected by ADH, but not by adenosine 3',5'-cyclic monophosphate.

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.

Water permeability and particle aggregates in ADH-, cAMP-, and forskolin-treated toad bladder

1987 ◽  
Vol 253 (1) ◽  
pp. F120-F125 ◽  
Author(s):  
W. A. Kachadorian ◽  
R. A. Coleman ◽  
J. B. Wade
Keyword(s):  
Water Permeability ◽  
Water Movement ◽  
Toad Bladder ◽  
Intracellular Camp ◽  
Tissue Water ◽  
Membrane Area ◽  
Luminal Membrane ◽  
Osmotic Water ◽  
Particle Aggregates ◽  
The Relationship

Osmotic water flow was used to evaluate total tissue water permeability (Ptissue), and luminal membrane particle aggregates, presumed sites for transmembrane water movement, were quantified to assess luminal membrane water permeability, in bladders treated with maximally stimulating concentrations of antidiuretic hormone (ADH), adenosine 3',5'-cyclic monophosphate (cAMP), and forskolin. Aggregates were as numerous and occupied the same fractional area of the luminal membrane in response to cAMP treatment (10 mM) as treatment with ADH (20 mU/ml). Ptissue in cAMP-treated tissues, however, was only half of that induced by ADH (P less than 0.001). A similar disparity in the relationship between aggregates and Ptissue occurred for additional bladders treated with 50 microM forskolin, which is known to increase endogenous cAMP to levels much greater than caused by maximally stimulating concentrations of ADH. Although Ptissue achieved with forskolin was the same in paired bladders treated with ADH, aggregates were far more numerous (P less than 0.05) and occupied much more membrane area (P less than 0.05) with forskolin. These observations are consistent with the view that aggregate appearance in the luminal membrane is a function of intracellular cAMP. The finding that the hydrosmotic response of toad bladder to both cAMP and forskolin compared with ADH stimulation is reduced relative to measured changes in luminal membrane aggregates suggests that the effect of ADH in altering water permeability involves additional regulation via a non-cAMP-mediated mechanism. This latter event would appear to be by an effect of ADH on the permeability of a resistance at a postluminal membrane site and/or possibly on the permeability of aggregates in the luminal membrane.

Dynamics of apical membrane responses to ADH in amphibian bladder

1989 ◽  
Vol 257 (5) ◽  
pp. R998-R1003 ◽  
Author(s):  
J. B. Wade
Keyword(s):  
Water Permeability ◽  
Apical Membrane ◽  
Function Analysis ◽  
Membrane Dynamics ◽  
Toad Urinary Bladder ◽  
Osmotic Gradient ◽  
Apical Surface ◽  
Dynamic Feedback ◽  
Particle Aggregates ◽  
Intracellular Vesicles

The dynamic insertion and retrieval of membrane at the apical surface plays an important role in the action of antidiuretic hormone (ADH). The addition of membrane with water channels is a crucial event in initiating the water permeability response. ADH-stimulated bladders display distinctive differentiations in the apical membrane that represent sites where intracellular vesicles carrying intramembrane particle aggregates have fused with the apical surface. In the absence of an osmotic gradient these fusion sites appear to be relatively stable structures, but in the presence of an osmotic gradient there seems to be continuous addition and retrieval of membrane during sustained exposure to ADH. It is now clear that a dynamic feedback process is present, such that the water permeability of the apical membrane is adjusted by retrieval or addition of membrane depending on the magnitude of the transepithelial osmotic gradient. Removal of ADH leads to a striking retrieval of apical membrane, and intact aggregates have been demonstrated in the membrane of the vesicles that form in the apical cytoplasm after reversal of the response. Structure-function analysis has provided unique information, demonstrating that membrane dynamics is central to the mechanism whereby ADH regulates osmotic permeability in the toad urinary bladder.

Sign in / Sign up

Export Citation Format

Share Document