scholarly journals STRUCTURE OF THE TOAD'S URINARY BLADDER AS RELATED TO ITS PHYSIOLOGY

1961 ◽  
Vol 10 (4) ◽  
pp. 529-553 ◽  
Author(s):  
Lee D. Peachey ◽  
Howard Rasmussen
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Urinary Bladder ◽  
Plasma Membranes ◽  
Goblet Cells ◽  
Mucosal Surface ◽  
In Vitro Experiments ◽  
Granular Component ◽  
Mucosal Surfaces

The structure of the urinary bladder of the toad Bufo marinus was studied by light and electron microscopy. The epithelium covering the mucosal surface of the bladder is 3 to 10 microns thick and consists of squamous epithelial cells, goblet cells, and a third class of cells containing many mitochondria and possibly representing goblet cells in early stages of their secretory cycle. This epithelium is supported on a lamina propria 30 to several hundred microns thick and containing collagen fibrils, bundles of smooth muscle fibers, and blood vessels. The serosal surface of the bladder is covered by an incomplete mesothelium. The cytoplasm of the squamous epithelial cells, which greatly outnumber the other types of cells, is organized in a way characteristic of epithelial secretory cells. Mitochondria, smooth and rough surfaced endoplasmic reticulum, a Golgi apparatus, "multivesicular bodies," and isolated particles and vesicles are present. Secretion granules are found immediately under the plasma membranes of the free surfaces of the epithelial cells and are seen to fuse with these membranes and release their contents to contribute to a fibrous surface coating found only on the free mucosal surfaces of the cells. Beneath the plasma membranes on these surfaces is an additional, finely granular component. Lateral and basal plasma membranes are heavily plicated and appear ordinary in fine structure. The cells of the epithelium are tightly held together by a terminal bar apparatus and sealed together, with an intervening space of only 0.02 mµ near the bladder lumen, in such a way as to prevent water leakage between the cells. It is demonstrated in in vitro experiments that water traversing the bladder wall passes through the cytoplasm of the epithelial cells and that a vesicle transport mechanism is not involved. In vitro experiments also show that the basal (serosal) surfaces of the epithelial cells are freely permeable to water, while the free (mucosal) surfaces are normally relatively impermeable but become permeable when the serosal surface of the bladder is treated with neurohypophyseal hormones. The permeability barrier found at the mucosal surface may be represented, structurally, either by the filamentous layer lying external to the plasma membrane, by the intracellular, granular component found just under the plasma membrane, or by both of these components of the mucosal surface complex. The polarity of the epithelial sheet is emphasized and related to the physiological role of the urinary bladder in amphibian water balance mechanisms.

Release of cyclic AMP by toad urinary bladder

1975 ◽  
Vol 228 (3) ◽  
pp. 954-958 ◽  
Author(s):  
S Urakabe ◽  
JS Handler ◽  
J Orloff
Keyword(s):  
Epithelial Cells ◽  
Urinary Bladder ◽  
Cyclic Amp ◽  
Cell Membrane ◽  
Water Permeability ◽  
Ringer Solution ◽  
Mucosal Surface ◽  
Toad Urinary Bladder ◽  
Solution Bathing

Cyclic AMP accumulates in the Ringer solution bathing the toad urinary bladder in vitro. At least 4 times more cyclic AMP is released into the solution bathing the serosal surface than into the solution bathing the mucosal surface. Most of the cyclic AMP originates in the epithelial cells rather than the stroma. Vasopressin increased the content of cyclic AMP in the epithelial cells and increases the amount of cyclic AMP in the Ringer solution. Since there is not an increase in medium cyclic AMP when cell cyclic AMP levels are increased by theophylline, it is suggested that theophylline may reduce the permeability of the cell membrane to cyclic AMP. Finally, it is demonstrated that 10 mM NaF increase the amount of cyclic AMP in the epithelial cells and in the solution bathing the bladder, but block the effect of vasopressin on water permeability, presumably at a step subsequent to the formation of cyclic AMP.

Membrane microdomains: lessons from microscopy

1995 ◽  
Vol 53 ◽  
pp. 776-777
Author(s):  
J.M. Robinson ◽  
J.M Oliver
Keyword(s):  
Spatial Distribution ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Cell Types ◽  
Imaging Modalities ◽  
Membrane Microdomains ◽  
Membrane Domains ◽  
Lateral Heterogeneity ◽  
Functional Importance

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.

Effects of oviductal proteins, including heat shock 70 kDa protein 8, on survival of ram spermatozoa over 48 h in vitro

2009 ◽  
Vol 21 (3) ◽  
pp. 408 ◽  
Author(s):  
R. E. Lloyd ◽  
R. M. A. Elliott ◽  
A. Fazeli ◽  
P. F. Watson ◽  
W. V. Holt
Keyword(s):  
Plasma Membrane ◽  
Heat Shock ◽  
Membrane Proteins ◽  
Epithelial Cells ◽  
Beneficial Effect ◽  
Active Component ◽  
Apical Plasma Membrane ◽  
Series Of Experiments ◽  
Dose Dependent

Following insemination, ram spermatozoa are transported to the isthmus region of the oviduct where they bind to the oviductal epithelial cells (OEC), remaining viable for several hours. The aim of the present study was to begin to decipher which component(s) of the ewe oviduct actively participates in maintaining the viability of ram spermatozoa. A series of experiments was conducted to investigate whether: (1) soluble OEC apical plasma membrane proteins (sAPM) isolated from ewes prolong survival of ram spermatozoa over an extended (48 h) coincubation period at 39°C; (2) a recombinant form of one of these oviductal proteins, namely heat shock 70 kDa protein 8 (HSPA8), prolongs survival of ram spermatozoa; and (3) pretreatment with HSPA8 antibody compromises the ability of sAPM to prolong the survival of ram spermatozoa. Both sAPM and recombinant HSPA8 had a beneficial effect on the viability of ram spermatozoa during coincubation, although both these effects were dose dependent. In contrast, pretreatment with HSPA8 antibody significantly negated the ability of sAPM to maintain the viability of ram spermatozoa. These findings suggest that HSPA8 is an active component of the ewe oviduct that participates in maintaining the viability of ram spermatozoa. This is a potentially valuable observation given that there is a great deal of room for improving existing diluents for storing fresh ram semen.

scholarly journals Surface membrane vesicles from mononuclear cells stimulate erythroid stem cells to proliferate in culture

Blood ◽  
1982 ◽  
Vol 60 (3) ◽  
pp. 583-594 ◽  
Author(s):  
N Dainiak ◽  
CM Cohen
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Mononuclear Cells ◽  
Surface Membrane ◽  
Freeze Fracture ◽  
Membrane Vesicles ◽  
Cell Types ◽  
Target Cells ◽  
Freeze Fracture Electron Microscopy

Abstract In order to examine the contribution of cell surface materials to erythroid burst-promoting activity (BPA), we separated media conditioned by a variety of human cell types into pellets and supernatants by centrifugation. When added to serum-restricted cultures of nonadherent human marrow cells, pellets contained about half of the total stimulatory activity. Freeze-fracture electron microscopy of the pellets revealed the presence of unilamellar membrane vesicles ranging from 0.10 to 0.40 microM in diameter. The amount of BPA in culture increased with added vesicle concentration in a saturable fashion. Preparation of leukocyte conditioned medium (LCM) from 125I-wheat germ agglutinin labeled cells and studies comparing the glycoprotein composition of vesicles with that of leukocyte plasma membranes suggest that LCM-derived vesicles are of plasma membrane origin. Moreover, partially purified leukocyte plasma membrane preparations also contained BPA. While disruption of vesicles by freezing/thawing and hypotonic lysis did not alter BPA, heat, trypsin, or pronase treatment removed greater than 65% of BPA, implying that vesicle surface rather than intravesicular molecules express BPA. Results of BPA assays performed in two-layer clots indicated that proximity to target cells is required for vesicle BPA expression. We conclude that membrane vesicles spontaneously shed from cell surfaces may be important regulators of erythroid burst proliferation in vitro.

A reinvestigation of the function of the mammalian urinary bladder

1977 ◽  
Vol 232 (3) ◽  
pp. F187-F195 ◽  
Author(s):  
S. A. Lewis
Keyword(s):  
Urinary Bladder ◽  
Membrane Surface ◽  
Apical Cell ◽  
Membrane Damage ◽  
In Vitro Experiments ◽  
Apical Cell Membrane ◽  
Cell Membrane Damage ◽  
Using Data

The function of adult mammalian urinary bladder is evaluated in light of recent in vitro experiments. The discrepancy between in vivo and in vitro experimental results is examined and a possible solution proposed. Techniques for eliminating edge damage and measuring apical membrane surface area are described. A new chamber design for microelectrode studies is illustrated. The possibility of apical cell membrane damage caused by microelectrodes is critically examined and tested using the polyene antibiotic Nystatin. Using data from transepithelial and microelectrode experiments, a model for net Na+ transport across the bladder is proposed and then critically analyzed. The possible clinical implications of the in vitro experiments are briefly discussed.

Modulation of Ca2+ influx by a mediator released from human tracheal epithelial cells exposed to ozone in vitro

1995 ◽  
Vol 268 (4) ◽  
pp. L558-L564 ◽  
Author(s):  
Q. S. Qu ◽  
L. C. Chen
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Health Effects ◽  
Cellular Function ◽  
Vital Role ◽  
Tracheal Epithelial Cells ◽  
Cell Lysate ◽  
Tracheal Epithelial ◽  
Normal Cellular Function

Intracellular free Ca2+ ([Ca2+]i) plays a vital role both in maintaining normal cellular function and in cell killing. Few studies have been published regarding its role in ozone (O3)-induced health effects. This study investigated the effect and mechanism of O3 exposure on [Ca2+]i in human tracheal epithelial (HTE) cells. HTE cells grown on Costar Transwell inserts with a liquid-gas interface were exposed to 0, 0.05, 0.1, 0.2 and 0.4 ppm O3 at 37 degrees C for 1 h. After exposure, [Ca2+]i was measured using the fluorescent dye Fluo 3. O3 at 0.4 ppm produced a significant increase in [Ca2+]i, and the increases in [Ca2+]i were blocked by verapamil and 8-(diethylamino)-octyl-3,4,5,-trimethoxybenzoate (TMB-8). These results suggest that the O3-induced [Ca2+]i elevation may involve both Ca2+ release from internal stores and Ca2+ influx across the plasma membrane. Furthermore, both buffer and cell lysate of HTE cells exposed to 0.4 ppm O3 caused a rapid increase in [Ca2+]i of THP-1 human phagocytic monocytes, but the buffer and lysate from air exposed cells did not. These results suggest that O3 exposure causes HTE cells to release a diffusible mediator from the empty Ca(2+)-storing organelle and may be responsible for the sustained and persistent [Ca2+]i elevation in HTE cells exposed to 0.4 ppm O3.

scholarly journals The Vitamin D Receptor Is Present in Caveolae-Enriched Plasma Membranes and Binds 1α,25(OH)2-Vitamin D3in Vivo and in Vitro

2004 ◽  
Vol 18 (11) ◽  
pp. 2660-2671 ◽  
Author(s):  
Johanna A. Huhtakangas ◽  
Christopher J. Olivera ◽  
June E. Bishop ◽  
Laura P. Zanello ◽  
Anthony W. Norman
Keyword(s):  
Vitamin D ◽  
Plasma Membrane ◽  
Vitamin D Receptor ◽  
Plasma Membranes ◽  
Binding Protein ◽  
Kidney Tissue ◽  
Mouse Lung ◽  
Nuclear Fraction

Abstract The steroid hormone 1α,25(OH)2-vitamin D3 (1,25D) regulates gene transcription through a nuclear receptor [vitamin D receptor (VDR)] and initiation of rapid cellular responses through a putative plasma membrane-associated receptor (VDRmem). This study characterized the VDRmem present in a caveolae-enriched membrane fraction (CMF), a site of accumulation of signal transduction agents. Saturable and specific [3H]-1,25D binding in vitro was found in CMF of chick, rat, and mouse intestine; mouse lung and kidney; and human NB4 leukemia and rat ROS 17/2.8 osteoblast-like cells; in all cases the 1,25D KD binding dissociation constant = 1–3 nm. Our data collectively support the classical VDR being the VDRmem in caveolae: 1) VDR antibody immunoreactivity was detected in CMF of all tissues tested; 2) competitive binding of [3H]-1,25D by eight analogs of 1,25D was significantly correlated between nuclei and CMF (r2 = 0.95) but not between vitamin D binding protein (has a different ligand binding specificity) and CMF; 3) confocal immunofluorescence microscopy of ROS 17/2.8 cells showed VDR in close association with the caveolae marker protein, caveolin-1, in the plasma membrane region; 4) in vivo 1,25D pretreatment reduced in vitro [3H]-1,25D binding by 30% in chick and rat intestinal CMF demonstrating in vivo occupancy of the CMF receptor by 1,25D; and 5) comparison of [3H]-1,25D binding in VDR KO and WT mouse kidney tissue showed 85% reduction in VDR KO CMF and 95% reduction in VDR KO nuclear fraction. This study supports the presence of VDR as the 1,25D-binding protein associated with plasma membrane caveolae.

scholarly journals Carbohydrate mediation of boar sperm binding to oviductal epithelial cells in vitro

Reproduction ◽  
2001 ◽  
pp. 305-315 ◽  
Author(s):  
CE Green ◽  
J Bredl ◽  
WV Holt ◽  
PF Watson ◽  
A Fazeli
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Mammalian Species ◽  
Free Cell ◽  
Carbohydrate Recognition ◽  
Sperm Binding ◽  
Oviductal Epithelium ◽  
Species Specific

After mating, mammalian spermatozoa are transported to the lower oviductal isthmus. Spermatozoa are sequestered at the isthmus by attaching and interacting with oviductal epithelial cells, hence forming a sperm reservoir. In several mammalian species, specific carbohydrates mediate sperm-oviductal epithelial cell binding. A quantitative in vitro free cell bioassay was developed to investigate the involvement of carbohydrate recognition in pig sperm-oviductal epithelial cell interactions. This assay was validated. The sensitivity of the assay was such that it was possible to discriminate between different sperm concentrations and sperm-oviductal epithelial cell co-incubation periods, spermatozoa with damaged plasma membranes and epithelial cells of non-reproductive origin. Optimal conditions were used to incubate spermatozoa and oviductal epithelial cells in the presence of six hexose sugars at concentrations of 0, 2, 10 and 50 mmol l(-1). A significant (P < or = 0.05) reduction in the binding of spermatozoa to the oviductal epithelium was detected with 2, 10 and 50 mmol maltose l(-1), 50 mmol lactose l(-1) and 50 mmol mannose l(-1). These findings support the hypothesis that attachment of pig spermatozoa to oviductal epithelium before fertilization is mediated by carbohydrate recognition.

scholarly journals In vitro maintenance of boar sperm viability by a soluble fraction obtained from oviductal apical plasma membrane preparations

Reproduction ◽  
2003 ◽  
pp. 509-517 ◽  
Author(s):  
A Fazeli ◽  
RM Elliott ◽  
AE Duncan ◽  
A Moore ◽  
PF Watson ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Current Knowledge ◽  
Biologically Active ◽  
Apical Plasma Membrane ◽  
Sperm Viability ◽  
Boar Sperm ◽  
Membrane Contact ◽  
Vitro Model

Oviductal apical plasma membrane fractions have been successfully used to provide an in vitro model to study the role of direct membrane contact in sperm-oviduct interactions. Apical plasma membrane preparations from pig oviductal tissues show a dose-response in their ability to maintain boar sperm viability in vitro. Membrane preparations obtained from other tissues (lung and duodenum) are incapable of maintaining boar sperm viability to the same extent as oviductal tissue. The present study examined the validity of two hypotheses that arise from current knowledge of sperm-oviduct interactions, namely, that (i) apical plasma membranes prepared from ampullar regions of the oviduct are less effective than those from isthmus regions, and (ii) sperm survival is more effective in apical plasma membrane preparations derived from follicular phase oviducts than those derived from luteal phase oviducts. Both hypotheses were proved false. The nature of the active component(s) in the oviductal apical plasma membrane fractions was further investigated. Heat treatment (100 degrees C for 20 min) diminished the capacity of membranes to support boar sperm viability. Furthermore, a soluble salt-extracted fraction obtained from oviductal apical plasma membrane preparations was biologically active and supported boar sperm viability in vitro. This may indicate that the active factor(s) responsible for the maintenance of boar sperm viability is not an integral part of oviductal membranes and is peripherally bound to these membranes.

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