Selective Release of Apical Membrane Enzymes from Cultured Renal Epithelia by Phosphatidylinositol-Specific Phospholipase C

1993 ◽  
Vol 16 (6) ◽  
pp. 299-310 ◽  
Author(s):  
Alexandra Netzer ◽  
Gerhard Gstraunthaler
Keyword(s):  
Phospholipase C ◽  
Apical Membrane ◽  
Renal Epithelia ◽  
Membrane Enzymes ◽  
Cultured Renal Epithelia

Expression and molecular regulation of Na(+)-K(+)-ATPase after renal ischemia

1994 ◽  
Vol 267 (1) ◽  
pp. F75-F85 ◽  
Author(s):  
S. K. Van Why ◽  
A. S. Mann ◽  
T. Ardito ◽  
N. J. Siegel ◽  
M. Kashgarian
Keyword(s):  
Enzyme Production ◽  
Time Course ◽  
Apical Membrane ◽  
Proximal Tubules ◽  
Renal Ischemia ◽  
Beta Subunit ◽  
Molecular Regulation ◽  
Beta Subunits ◽  
Renal Epithelia ◽  
Subunit Mrna

Renal ischemia causes redistribution of Na(+)-K(+)-adenosinetriphosphatase (Na(+)-K(+)-ATPase) to the apical membrane of proximal tubules. We determined the time course of regeneration of Na(+)-K(+)-ATPase polarity and sought evidence of increased enzyme production during recovery as a means to restore polarity. Anesthetized rats underwent 45 min renal ischemia and reflow of 15 min, 2 h, 6 h, and 24 h. Immunofluorescent and electron microscopy showed loss of strict basolateral localization of Na(+)-K(+)-ATPase at 15 min reflow with repolarization by 24 h in sublethally injured cells. Both alpha 1- and beta-subunits were only in microsomal fractions at all reflow intervals. Immunodetectable levels of both subunits declined to 60-70% of control by 24 h reflow. Levels of mRNA for each subunit declined in parallel through 24 h to 55% of control. Overall transcription was profoundly depressed through 6 h but had recovered to near control by 24 h. Specific transcription of alpha 1- and beta-subunit mRNA was markedly decreased after ischemia and only partially recovered by 24 h. These results suggest that recycling of misplaced units rather than new Na(+)-K(+)-ATPase production is the means by which renal epithelia initially repolarize after ischemic injury.

Platinum Complex Toxicity in Cultured Renal Epithelia

2004 ◽  
Vol 14 (4-6) ◽  
pp. 431-440 ◽  
Author(s):  
Thomas Ludwig ◽  
Hans Oberleithner
Keyword(s):  
Platinum Complex ◽  
Renal Epithelia ◽  
Cultured Renal Epithelia

Assay of apical membrane enzymes based on fluorogenic substrates

1992 ◽  
Vol 200 (2) ◽  
pp. 352-358 ◽  
Author(s):  
Denise L. Blackmon ◽  
Alastair J.M. Watson ◽  
Marshall H. Montrose
Keyword(s):  
Apical Membrane ◽  
Fluorogenic Substrates ◽  
Membrane Enzymes

Polarity of transport of 2-deoxy-d-glucose and d-glucose by cultured renal epithelia (LLC-PK1)

1992 ◽  
Vol 1110 (2) ◽  
pp. 209-217 ◽  
Author(s):  
John H. Miller ◽  
James M. Mullin ◽  
Elizabeth McAvoy ◽  
Arnost Kleinzeller
Keyword(s):  
Renal Epithelia ◽  
Cultured Renal Epithelia

scholarly journals Selective release of plasma-membrane enzymes from rat hepatocytes by a phosphatidylinositol-specific phospholipase C

1980 ◽  
Vol 187 (1) ◽  
pp. 277-280 ◽  
Author(s):  
S D Shukla ◽  
R Coleman ◽  
J B Finean ◽  
R H Michell
Keyword(s):  
Alkaline Phosphatase ◽  
Plasma Membrane ◽  
Cell Surface ◽  
Phospholipase C ◽  
Inositol Phosphate ◽  
Rat Hepatocytes ◽  
Isolated Hepatocytes ◽  
Membrane Enzymes

When isolated hepatocytes are incubated with phosphatidylinositol-specific phospholipase C, three cell-surface enzymes show markedly different behaviour. Most of the alkaline phosphatase is released at very low values of phosphatidylinositol hydrolysis, whereas further phosphatidylinositol hydrolysis releases only a maximum of about one-third of the 5′-nucleotidase. Alkaline phosphodiesterase I is not released. If cells containing phosphatidyl[3H]inositol are similarly treated, then the released [3H]inositol is in the form of inositol phosphate: no evidence has been obtained for any covalent association between released [3H]inositol and alkaline phosphatase.

Role of PKC isozyme III (γ) in water transport in amphibian urinary bladder

1992 ◽  
Vol 50 (1) ◽  
pp. 796-797
Author(s):  
A.J Mia ◽  
L.X. Oakford ◽  
P.D. Thompson ◽  
Z.H. Ning ◽  
T. Yorio
Keyword(s):  
Urinary Bladder ◽  
Water Flow ◽  
Phorbol Esters ◽  
Apical Membrane ◽  
Protein A ◽  
Water Channels ◽  
Renal Epithelia ◽  
Amphibian Urinary Bladder ◽  
Pkc Isozymes

Vasopressin stimulated water flow across renal epithelia is thought to occur through a V2 receptor coupled to adenylcyclase. The increase in water flow occurs as a result of a fusion of water channels with the apical membrane and is indicative of an increase in membrane capacitance following hormone addition.What controls the cycling of water channels and their insertion into the membrane is uncertain. Our laboratory has demonstrated that renal epithelia as well as amphibian urinary bladder membranes, contain a vasopressin V1 receptor which upon activation results in the breakdown of phosphoinositide and the formation of inositol triphosphate and diacylglycerol, the latter an activator of protein kinase C (PKC). The initiation of transepithelial water flow also appears to involve V1 receptors and possibly activation of PKC. To test this hypothesis, we have been using activators of PKC, such as phorbol esters and mezerein, as pharmacological tools to determine if PKC activation results in similar physiological responses as the hormone. Several PKC isozymes, upon activation, are known to be translocated to the apical membrane as visualized by FITC immunofluorescence. Previously, we reported co-localization of PKC subtypes I (γ) and II (β) in toad urinary bladders using monoclonal antibodies and protein A-gold probes. This report includes the localization of PKC subtype III (α) and its distribution pattern using immunogold labeling.

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