Aquaporin-1 deletion reduces osmotic water permeability and cerebrospinal fluid production

2003 ◽  
pp. 525-528 ◽  
Author(s):  
K. Oshio ◽  
Y. Song ◽  
A. S. Verkman ◽  
Geoffrey T. Manley
Keyword(s):  
Cerebrospinal Fluid ◽  
Water Permeability ◽  
Osmotic Water Permeability ◽  
Aquaporin 1 ◽  
Osmotic Water ◽  
Fluid Production

Expression of Aquaporin-1 in the Peritoneal Tissues: Localization and Regulation by Hyperosmolality

2002 ◽  
Vol 22 (3) ◽  
pp. 307-315 ◽  
Author(s):  
Tomoko Ota ◽  
Michio Kuwahara ◽  
Shuling Fan ◽  
Yoshio Terada ◽  
Takashi Akiba ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Water Permeability ◽  
Water Channel ◽  
Mesothelial Cells ◽  
Scattering Method ◽  
Osmotic Water Permeability ◽  
Peritoneal Mesothelial Cells ◽  
Aquaporin 1 ◽  
Osmotic Water ◽  
Aqp1 Expression

Objective The purpose of this study was to determine the localization of the aquaporin-1 (AQP1) water channel in peritoneal tissues and the effect of hyperosmolality on the peritoneal expression and function of AQP1. Methods Immunohistochemical localization of AQP1 was identified in rat peritoneal tissues. Cultured rat peritoneal mesothelial cells (RPMCs) were exposed to hyperosmolality by adding 4% glucose to the culture medium. After 1 hour, 4 hours, 24 hours, and 48 hours, AQP1 was identified by semiquantitative immunoblot and immunocytochemistry. Osmotic water permeability was measured using a light-scattering method. Results Immunohistochemistry of rat peritoneal tissues showed the presence of AQP1 in mesothelial cells, venular endothelial cells, and capillary endothelial cells, but not in arteriole and interstitial cells. Semiquantitative immunoblot revealed that exposure to hyperosmolality significantly increased AQP1 expression after 24 hours in whole RPMC lysates (3.3-fold at 24 hours and 3.9-fold at 48 hours). Consistent with the immunoblot, osmotic water permeability of RPMC was augmented 1.7-fold and 2.7-fold after 1 hour and 24 hours, respectively, in a hyperosmotic environment. In RPMC membrane fractions, AQP1 expression was significantly increased after 1 hour of exposure to hyperosmolality (3.9-fold at 1 hour, 7.1-fold at 4 hours, and 8.7-fold at 24 hours). Immunocytochemistry of RPMCs showed that AQP1 was gradually redistributed from the perinuclear area to the peripheral cytoplasm, and then to the plasma membrane after a 1-hour hyperosmotic challenge, suggesting hyperosmolality-induced translocation of AQP1. Upregulation of AQP1 was also observed in the omentum of rats loaded intraperitoneally with hyperosmotic dialysate every day for 10 weeks. Conclusion AQP1 is widely distributed in the peritoneal cavity and may provide the major aqueous pathway across the peritoneal barrier. In addition, our findings suggested that hyperosmolality increases AQP1-dependent water permeability in peritoneal tissues by regulating the translocation and synthesis of AQP1 protein.

Acetazolamide inhibits osmotic water permeability by interaction with aquaporin-1

2006 ◽  
Vol 350 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Junwei Gao ◽  
Xiaohua Wang ◽  
Yongjie Chang ◽  
Jianzhao Zhang ◽  
Qianliu Song ◽  
...  
Keyword(s):  
Water Permeability ◽  
Osmotic Water Permeability ◽  
Aquaporin 1 ◽  
Osmotic Water

scholarly journals Relative CO2/NH3 selectivities of mammalian aquaporins 0–9

2013 ◽  
Vol 304 (10) ◽  
pp. C985-C994 ◽  
Author(s):  
R. Ryan Geyer ◽  
Raif Musa-Aziz ◽  
Xue Qin ◽  
Walter F. Boron
Keyword(s):  
Plasma Membrane ◽  
Water Permeability ◽  
Xenopus Oocytes ◽  
Video Microscopy ◽  
Osmotic Water Permeability ◽  
Permeability Ratio ◽  
Diverse Range ◽  
Surface Ph ◽  
Aquaporin 1 ◽  
Osmotic Water

Previous work showed that aquaporin 1 (AQP1), AQP4-M23, and AQP5 each has a characteristic CO2/NH3 and CO2/H2O permeability ratio. The goal of the present study is to characterize AQPs 0–9, which traffic to the plasma membrane when heterologously expressed in Xenopus oocytes. We use video microscopy to compute osmotic water permeability ( Pf) and microelectrodes to record transient changes in surface pH (ΔpHS) caused by CO2 or NH3 influx. Subtracting respective values for day-matched, H2O-injected control oocytes yields the channel-specific values Pf* and ΔpHS*. We find that Pf* is significantly >0 for all AQPs tested except AQP6. (ΔpHS*)CO2 is significantly >0 for AQP0, AQP1, AQP4-M23, AQP5, AQP6, and AQP9. (ΔpHS*)NH3 is >0 for AQP1, AQP3, AQP6, AQP7, AQP8, and AQP9. The ratio (ΔpHS*)CO2/ Pf* falls in the sequence AQP6 (∞) > AQP5 > AQP4-M23 > AQP0 ≅ AQP1 ≅ AQP9 > others (0). The ratio (ΔpHS*)NH3/ Pf* falls in the sequence AQP6 (∞) > AQP3 ≅ AQP7 ≅ AQP8 ≅ AQP9 > AQP1 > others (0). Finally, the ratio (ΔpHS*)CO2/(−ΔpHS*)NH3 falls in the sequence AQP0 (∞) ≅ AQP4-M23 ≅ AQP5 > AQP6 > AQP1 > AQP9 > AQP3 (0) ≅ AQP7 ≅ AQP8. The ratio (ΔpHS*)CO2/(−ΔpHS*)NH3 is indeterminate for both AQP2 and AQP4-M1. In summary, we find that mammalian AQPs exhibit a diverse range of selectivities for CO2 vs. NH3 vs. H2O. As a consequence, by expressing specific combinations of AQPs, cells could exert considerable control over the movements of each of these three substances.

Osmotic water permeability of aquaporin-1 under radial tensile and compressive stimuli

Desalination ◽  
2020 ◽  
Vol 492 ◽  
pp. 114524
Author(s):  
Shaghayegh Bahari ◽  
Reza Davarnejad ◽  
Omid Bavi ◽  
Seyed Vahid Mohammadi
Keyword(s):  
Water Permeability ◽  
Osmotic Water Permeability ◽  
Aquaporin 1 ◽  
Osmotic Water

scholarly journals Osmotic water permeability of human red cells.

1981 ◽  
Vol 77 (5) ◽  
pp. 549-570 ◽  
Author(s):  
T C Terwilliger ◽  
A K Solomon
Keyword(s):  
Systematic Error ◽  
Water Permeability ◽  
Perturbation Technique ◽  
Mean Value ◽  
Red Cells ◽  
Osmotic Water Permeability ◽  
Osmotic Water ◽  
New Perturbation ◽  
The Relationship ◽  
Human Red Cells

The osmotic water permeability of human red cells has been reexamined with a stopped-flow device and a new perturbation technique. Small osmotic gradients are used to minimize the systematic error caused by nonlinearities in the relationship between cell volume and light scattering. Corrections are then made for residual systematic error. Our results show that the hydraulic conductivity, Lp, is essentially independent of the direction of water flow and of osmolality in the range 184-365 mosM. the mean value of Lp obtained obtained was 1.8 +/- 0.1 (SEM) X 10-11 cm3 dyne -1 s-1.

Cell osmotic water permeability of isolated rabbit proximal straight tubules

1982 ◽  
Vol 242 (4) ◽  
pp. F321-F330 ◽  
Author(s):  
E. Gonzalez ◽  
P. Carpi-Medina ◽  
G. Whittembury
Keyword(s):  
Surface Area ◽  
Water Flow ◽  
Water Permeability ◽  
Permeability Coefficient ◽  
Osmotic Water Permeability ◽  
Water Permeability Coefficient ◽  
Osmotic Water ◽  
Straight Tubules ◽  
Tubular Surface ◽  
Set Up

Proximal straight tubules were dissected and mounted in a chamber with their lumina occluded. The well-stirred bath could be 95% changed within 84 ms to set up osmotic gradients (delta Coi) across the peritubular cell aspect. Volume changes (less than or equal to 10 pl/mm) were estimated from continuous records of diameter changes (error less than 0.1 micrometers). delta Coi greater than or equal to 2-3 mosM could be discerned. delta Coi values from 10 to 44 mosM were used to evaluate Posc, the cell osmotic water permeability coefficient, and extrapolated to delta Coi = 0. Posc = 25.1 (+/- 2.3) X 10(-4) cm3.s-1.osM-1.cm2 tubular surface area-1. These values are lower than those reported for Pose, the transepithelial osmotic water permeability coefficient, and become lower if corrected for the real (infolded) peritubular cell surface area. Thus, for a given osmotic difference, transcellular water flow finds a higher resistance than paracellular water flow. Experiments were also performed with delta Coi greater than 100 mosM, but interpretation of these data is difficult because of the presence of volume regulatory phenomena and other undesirable effects.

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