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
1990 ◽  
Vol 258 (2) ◽  
pp. F237-F243
Author(s):  
H. W. Harris ◽  
J. S. Handler ◽  
R. Blumenthal

Antidiuretic hormone (ADH) stimulation of the toad urinary bladder causes intracellular vesicles called aggrephores to fuse with the apical plasma membrane of granular cells. Aggrephore membranes contain particle aggregates. Particle aggregates are believed to be water channels that cause large increases in the water permeability (PF) of the granular cell apical membrane. Removal of ADH causes the retrieval of particle aggregate-containing apical membrane via endocytosis and a decline in PF. We have previously shown that fluid phase markers are sequestered in these particle aggregate-containing vesicles during retrieval of the apical membrane and that these vesicles can be recovered in cell homogenates. We have now loaded these vesicles with the self-quenching fluorophore carboxyfluorescein (CF) to measure and compare their PF with that of CF-loaded resealed human erythrocyte ghosts. The membranes of these retrieved vesicles have a very high water permeability. The minimum PF of 99% of these vesicles is 4.5 X 10(-2) cm/s. This PF is comparable with that of erythrocyte ghosts (5.4 X 10(-2) cm/s) measured under identical conditions. We conclude that these vesicles are highly permeable to water, and this is consistent with their postulated function of retrieving water channels that have been inserted into the apical membrane in response to ADH.


1992 ◽  
Vol 263 (4) ◽  
pp. C908-C912 ◽  
Author(s):  
Y. Gao ◽  
N. Franki ◽  
F. Macaluso ◽  
R. M. Hays

Studies with the confocal microscope have shown that arginine vasopressin (AVP) depolymerizes F-actin in the apical region of the toad bladder granular cell. However, the resolution of the fluorescence microscope is not great enough to reveal the exact pattern of depolymerization or the relative extent to which microvillar and subapical membrane actin pools contribute to overall depolymerization. We have developed an electron microscopic immunogold method that shows a significant decrease in immunogold labeling of actin in the region just below the apical membrane, with the decrease most pronounced in regions adjacent to the microvilli. There was no significant change of immunogold labeling within the microvilli themselves. Our studies show a reorganization of the actin cytoskeleton in the region of the granular cell, where water channel-carrying vesicles are positioned and fuse in response to AVP.


1988 ◽  
Vol 255 (3) ◽  
pp. F375-F382 ◽  
Author(s):  
J. S. Handler

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.


1987 ◽  
Vol 253 (1) ◽  
pp. F120-F125 ◽  
Author(s):  
W. A. Kachadorian ◽  
R. A. Coleman ◽  
J. B. Wade

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.


1991 ◽  
Vol 260 (6) ◽  
pp. C1308-C1314
Author(s):  
L. M. Guay-Woodford ◽  
O. Platt ◽  
H. W. Harris

Epithelial cell polarity and vectorial transport require cytoskeletal proteins that maintain local cell membrane structure and mediate cytoplasmic vesicle movement. The cytoskeleton of leaky epithelia, such as the intestinal mucosa and renal proximal tubule cells, has been extensively studied. However, cytoskeletal studies in tight epithelia such as the mammalian collecting duct and toad urinary bladder generally have been confined to ultrastructural investigation. Recent research in nonepithelial cell types has identified an interesting family of cytoskeletal proteins. Present in multiple cell types, these protein 4.1 analogues share a number of similar functional characteristics, yet are structurally diverse. They are multiply phosphorylated by several different kinases, and phosphorylation regulates their associations with other cytoskeletal constituents, integral membrane components, and cytoplasmic vesicles. Using a combination of immunochemical and immunofluorescent techniques, we have demonstrated that toad bladder epithelial cells contain a 65-kDa analogue of human erythrocyte protein 4.1. Toad bladder epithelial cell protein 4.1 is structurally similar to its erythrocyte counterpart and is phosphorylated. This protein 4.1 species is present throughout the toad bladder granular cell cytoplasm, suggesting that it participates in multiple granular cell functions.


1992 ◽  
Vol 262 (3) ◽  
pp. C672-C677 ◽  
Author(s):  
K. Holmgren ◽  
K. E. Magnusson ◽  
N. Franki ◽  
R. M. Hays

Antidiuretic hormone (ADH) induces the fusion of cytoplasmic vesicles containing water channels with the apical membrane of the toad bladder granular cell. Fusion is accompanied by a 30% depolymerization of F-actin. We have used confocal microscopy to determine the region in the cell that undergoes depolymerization. Bladders were mounted in a split chamber, and control halves and halves stimulated by ADH for 15 min were fixed and then stained with rhodamine phalloidin. Vertical sections through the cells were obtained by confocal microscopy, and the fluorescence intensity of the apical and side regions of the cells was determined. To normalize the data, the apex-side intensity was determined for each cell, and these ratios measured for control and ADH-treated halves. In six paired experiments, the ratio for control halves was 3.69 +/- 0.50 and for ADH-treated halves was 2.61 +/- 0.33; the decrease was significant and in good agreement with earlier studies. Thus actin depolymerization takes place in a hormone-sensitive apical pool where vesicle fusion occurs and supports the view that actin depolymerization may be required for fusion.


1987 ◽  
Vol 253 (5) ◽  
pp. C707-C720 ◽  
Author(s):  
J. H. Hartwig ◽  
D. A. Ausiello ◽  
D. Brown

The apical plasma membrane of toad bladder granular cells undergoes a rapid and dramatic increase in water permeability in response to vasopressin stimulation. Previous studies have shown that this permeability increase is accompanied by characteristic changes in the morphology of this membrane and that these changes may be involved in the hormonal response. In this report, we have used the technique of rapid freezing and freeze drying to obtain high resolution stereo images of the surface of the granular cell apical plasma membrane before and during vasopressin stimulation. Using this approach, we confirmed that vasopressin induces a ridge-to-villus transformation of the cell surface even in the absence of osmotic water flow, but now show that this transformation occurs at least in part via a retraction of segments of preexisting ridges, rather than by the growth of new microvilli from the apical cell surface. This is also demonstrated by the finding that vasopressin induces the ridge-to-villus transformation of the cell surface even in the presence of cytochalasin D. In addition, the rapid-freeze, freeze-dry technique reveals that the surface glycocalyx of the epithelial cells consists of a complex, three-dimensional network of filaments that is heterogeneous among different cells. Finally, vasopressin-induced tubular invaginations of the apical plasma membrane were visualized in stereomicrographs, and the number and size of such invaginations were altered in the presence of cytochalasin D. These may represent surface images of vasopressin-induced exo- and endocytotic events that are related to membrane permeability changes.


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