scholarly journals Immunolocalization of the mercurial-insensitive water channel and glycerol intrinsic protein in epithelial cell plasma membranes.

1995 ◽  
Vol 92 (10) ◽  
pp. 4328-4331 ◽  
Author(s):  
A. Frigeri ◽  
M. A. Gropper ◽  
C. W. Turck ◽  
A. S. Verkman
Keyword(s):  
Epithelial Cell ◽  
Plasma Membranes ◽  
Water Channel ◽  
Intrinsic Protein ◽  
Cell Plasma

Lectin-gold labeling of glycoconjugates in normal and Brattleboro rat papilla: effect of vasopressin

1988 ◽  
Vol 254 (3) ◽  
pp. C450-C458 ◽  
Author(s):  
P. Weyer ◽  
D. Brown ◽  
L. Orci
Keyword(s):  
Epithelial Cell ◽  
Plasma Membranes ◽  
Collecting Duct ◽  
Helix Pomatia ◽  
Major Effect ◽  
Urinary Concentration ◽  
Brattleboro Rats ◽  
Cell Plasma ◽  
Collecting Ducts ◽  
Helix Pomatia Lectin

Some reports suggest that the plasma membrane glycocalyx of collecting duct epithelial cells, as well as interstitial glycoconjugates, may be involved in vasopressin action and urinary concentration. In view of this, we have used the lectin-gold technique to map and quantify Helix pomatia lectin (HPL)-binding sites in the inner medulla of kidneys from normal Long-Evans rats, vasopressin-deficient Brattleboro rats, and Brattleboro rats treated for up to 5 wk with exogenous vasopressin. The results show that the labeling of epithelial cell plasma membranes from collecting ducts and thin limbs of Henle is not different between normal and Brattleboro rats, and the labeling is not modified by chronic vasopressin treatment. In contrast, the heavy interstitial labeling seen in normal rats is virtually absent from Brattleboro rats, but it is progressively restored by chronic vasopressin treatment of Brattleboro rats. These results show that vasopressin does not modify HPL-binding glycoconjugates on epithelial cell plasma membranes, but that vasopressin treatment has a major effect on HPL-binding glycoconjugates in the medullary interstitium.

scholarly journals Polyphenols as Modulators of Aquaporin Family in Health and Disease

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Diana Fiorentini ◽  
Laura Zambonin ◽  
Francesco Vieceli Dalla Sega ◽  
Silvana Hrelia
Keyword(s):  
Plasma Membranes ◽  
Skin Diseases ◽  
Water Channel ◽  
Bioactive Molecules ◽  
Food Sources ◽  
Major Function ◽  
Cell Plasma ◽  
Original Analysis ◽  
Health And Disease

Polyphenols are bioactive molecules widely distributed in fruits, vegetables, cereals, and beverages. Polyphenols in food sources are extensively studied for their role in the maintenance of human health and in the protection against development of chronic/degenerative diseases. Polyphenols act mainly as antioxidant molecules, protecting cell constituents against oxidative damage. The enormous number of polyphenolic compounds leads to huge different mechanisms of action not fully understood. Recently, some evidence is emerging about the role of polyphenols, such as curcumin, pinocembrin, resveratrol, and quercetin, in modulating the activity of some aquaporin (AQP) isoforms. AQPs are integral, small hydrophobic water channel proteins, extensively expressed in many organs and tissues, whose major function is to facilitate the transport of water or glycerol over cell plasma membranes. Here we summarize AQP physiological functions and report emerging evidence on the implication of these proteins in a number of pathophysiological processes. In particular, this review offers an overview about the role of AQPs in brain, eye, skin diseases, and metabolic syndrome, focusing on the ability of polyphenols to modulate AQP expression. This original analysis can contribute to elucidating some peculiar effects exerted by polyphenols and can lead to the development of an innovative potential preventive/therapeutic strategy.

Biogenesis of Epithelial Cell Plasma Membranes

2008 ◽  
pp. 184-208
Author(s):  
Michael J. Rindler ◽  
Ivan Emanuilov Ivanov ◽  
Enrique J. Rodriguez-Boulan ◽  
David D. Sabatini
Keyword(s):  
Epithelial Cell ◽  
Plasma Membranes ◽  
Cell Plasma

Expanding roles of plant aquaporins in plasma membranes and cell organelles

2008 ◽  
Vol 35 (1) ◽  
pp. 1 ◽  
Author(s):  
Maki Katsuhara ◽  
Yuko T. Hanba ◽  
Katsuhiro Shiratake ◽  
Masayoshi Maeshima
Keyword(s):  
Water Transport ◽  
Plasma Membranes ◽  
Water Channel ◽  
Potential Gradient ◽  
Cell Organelles ◽  
Plasma Membrane Intrinsic Protein ◽  
Intrinsic Protein ◽  
Functional Regulation ◽  
Water Potential Gradient ◽  
Intracellular Localisation

Aquaporins facilitate water transport across biomembranes in a manner dependent on osmotic pressure and water-potential gradient. The discovery of aquaporins has facilitated research on intracellular and whole-plant water transport at the molecular level. Aquaporins belong to a ubiquitous family of membrane intrinsic proteins (MIP). Plants have four subfamilies: plasma-membrane intrinsic protein (PIP), tonoplast intrinsic protein (TIP), nodulin 26-like intrinsic protein (NIP), and small basic intrinsic protein (SIP). Recent research has revealed a diversity of plant aquaporins, especially their physiological functions and intracellular localisation. A few PIP members have been reported to be involved in carbon dioxide permeability of cells. Newly identified transport substrates for NIP members of rice and Arabidopsis thaliana have been demonstrated to transport silicon and boron, respectively. Ammonia, glycerol, and hydrogen peroxide have been identified as substrates for plant aquaporins. The intracellular localisation of plant aquaporins is diverse; for example, SIP members are localised on the ER membrane. There has been much progress in the research on the functional regulation of water channel activity of PIP members including phosphorylation, formation of hetero-oligomer, and protonation of histidine residues under acidic condition. This review provides a broad overview of the range of potential aquaporins, which are now believed to participate in the transport of several small molecules in various membrane systems in model plants, crops, flowers and fruits.

scholarly journals Insulin-induced rapid decrease of a major protein in fat cell plasma membranes.

1984 ◽  
Vol 259 (19) ◽  
pp. 12112-12116
Author(s):  
E J Schoenle ◽  
L D Adams ◽  
D W Sammons
Keyword(s):  
Plasma Membranes ◽  
Rapid Decrease ◽  
Major Protein ◽  
Fat Cell ◽  
Cell Plasma

scholarly journals Isolation and Characterization of Epididymal Epithelial Cell Plasma Membranes1

1988 ◽  
Vol 38 (1) ◽  
pp. 201-209 ◽  
Author(s):  
Stephen Byers ◽  
Laura Richardson ◽  
Craig Parker
Keyword(s):  
Epithelial Cell ◽  
Isolation And Characterization ◽  
Cell Plasma

scholarly journals Charged anaesthetics alter LM-fibroblast plasma-membrane enzymes by selective fluidization of inner or outer membrane leaflets

1986 ◽  
Vol 239 (2) ◽  
pp. 301-310 ◽  
Author(s):  
W D Sweet ◽  
F Schroeder
Keyword(s):  
Plasma Membrane ◽  
Active Site ◽  
Plasma Membranes ◽  
Local Anaesthetics ◽  
Cationic Drugs ◽  
Cell Plasma ◽  
Composition And Structure ◽  
Highly Sensitive ◽  
Functional Consequences ◽  
Anionic Drugs

The functional consequences of the differences in lipid composition and structure between the two leaflets of the plasma membrane were investigated. Fluorescence of 1,6-diphenylhexa-1,3,5-triene(DPH), quenching, and differential polarized phase fluorimetry demonstrated selective fluidization by local anaesthetics of individual leaflets in isolated LM-cell plasma membranes. As measured by decreased limiting anisotropy of DPH fluorescence, cationic (prilocaine) and anionic (phenobarbital and pentobarbital) amphipaths preferentially fluidized the cytofacial and exofacial leaflets respectively. Unlike prilocaine, procaine, also a cation, fluidized both leaflets of these membranes equally. Pentobarbital stimulated 5′-nucleotidase between 0.1 and 5 mM and inhibited at higher concentrations, whereas phenobarbital only inhibited, at higher concentrations. Cationic drugs were ineffective. Two maxima of (Na+ + K+)-ATPase activation were obtained with both anionic drugs. Only one activation maximum was obtained with both cationic drugs. The maximum in activity below 1 mM for all four drugs clustered about a single limiting anisotropy value in the cytofacial leaflet, whereas there was no correlation between activity and limiting anisotropy in the exofacial leaflets. Therefore, although phenobarbital and pentobarbital below 1 mM fluidized the exofacial leaflet more than the cytofacial leaflet, the smaller fluidization in the cytofacial leaflet was functionally significant for (Na+ + K+)-ATPase. Mg2+-ATPase was stimulated at 1 mM-phenobarbital, unaffected by pentobarbital and slightly stimulated by both cationic drugs at concentrations fluidizing both leaflets. Thus the activity of (Na+ + K+)-ATPase was highly sensitive to selective fluidization of the leaflet containing its active site, whereas the other enzymes examined were little affected by fluidization of either leaflet.

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