|
|
||||||||
AJP - Renal Physiology, Vol 267, Issue 4 516-F527, Copyright © 1994 by American Physiological Society
ARTICLES |
T. G. Hammond, P. J. Verroust, R. R. Majewski, K. E. Muse and T. D. Oberley
University of Wisconsin Hospitals and Clinics, William S. Middleton Memorial Veterans Affairs Hospital, Madison 53792.
The endosomal pathway of the rat renal cortex was labeled by intravenous infusion of fluorescent dextran small enough to cross the glomerular ultrafiltration barrier and be taken up by luminal endocytosis. A fraction containing entrapped fluorescein was isolated from a cortical homogenate after differential centrifugation and Percoll density gradient centrifugation. This fraction has been dubbed heavy endosomes. To our surprise, small-particle flow cytometry techniques demonstrated that heavy endosomes are homogeneous for entrapped fluorescein dextran and the presence of H(+)-adenosinetriphosphatase activity. The abundance of heavy endosomes, combined with the findings that true endosomal populations are identifiable in other renal cortical fractions, led us to test whether heavy endosomes had the attributes of intermicrovillar clefts. First, we tested whether heavy endosomes vesiculate in vivo or in vitro. Vesicle-by-vesicle flow cytometry analysis of uptake of fluorescein dextran added to the homogenate demonstrated that virtually all the vesicles form in vitro (99 +/- 2%, n = 4). Second, the fraction contains markers associated with intermicrovillar clefts: clathrin light chains, actin, glycoprotein gp280, and gp330, the "Heymann antigen." The presence of the brush border enzyme markers gamma-glutamyl transpeptidase and leucine aminopeptidase in > 99% of the heavy endosomes confirms that the vesicles are of apical origin. The activity of the enzymes colocalized with entrapped markers but was tenfold less than in brush-border membrane vesicles. Heavy endosomes isolated from the rat renal cortex vesiculate in vitro and contain several intermicrovillar markers.
This article has been cited by other articles:
![]() |
W. Van Driessche, J. L. Kreindler, A. B. Malik, S. Margulies, S. A. Lewis, and K.-J. Kim Interrelations/cross talk between transcellular transport function and paracellular tight junctional properties in lung epithelial and endothelial barriers Am J Physiol Lung Cell Mol Physiol, September 1, 2007; 293(3): L520 - L524. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Gonzalez-Villalobos, R. B. Klassen, P. L. Allen, K. Johanson, C. B. Baker, H. Kobori, L. G. Navar, and T. G. Hammond Megalin binds and internalizes angiotensin-(1-7) Am J Physiol Renal Physiol, May 1, 2006; 290(5): F1270 - F1275. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Gonzalez-Villalobos, R. B. Klassen, P. L. Allen, L. G. Navar, and T. G. Hammond Megalin binds and internalizes angiotensin II Am J Physiol Renal Physiol, February 1, 2005; 288(2): F420 - F427. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. B. Klassen, K. Crenshaw, R. Kozyraki, P. J. Verroust, L. Tio, S. Atrian, P. L. Allen, and T. G. Hammond Megalin mediates renal uptake of heavy metal metallothionein complexes Am J Physiol Renal Physiol, September 1, 2004; 287(3): F393 - F403. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Fisher and S. S. Margulies Na+-K+-ATPase activity in alveolar epithelial cells increases with cyclic stretch Am J Physiol Lung Cell Mol Physiol, October 1, 2002; 283(4): L737 - L746. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. C. Done, I. B. Leibiger, R. Efendiev, A. I. Katz, B. Leibiger, P.-O. Berggren, C. H. Pedemonte, and A. M. Bertorello Tyrosine 537 within the Na+,K+-ATPase alpha -Subunit Is Essential for AP-2 Binding and Clathrin-dependent Endocytosis J. Biol. Chem., May 3, 2002; 277(19): 17108 - 17111. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. Thome, L. Chen, P. Factor, V. Dumasius, B. Freeman, J. Iasha Sznajder, and S. Matalon Na,K-ATPase Gene Transfer Mitigates an Oxidant-Induced Decrease of Active Sodium Transport in Rat Fetal ATII Cells Am. J. Respir. Cell Mol. Biol., March 1, 2001; 24(3): 245 - 252. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. RADER, R. A. ORLANDO, X. LOU, and M. G. FARQUHAR Characterization of ANKRA, a Novel Ankyrin Repeat Protein that Interacts with the Cytoplasmic Domain of Megalin J. Am. Soc. Nephrol., December 1, 2000; 11(12): 2167 - 2178. [Abstract] [Full Text] |
||||
![]() |
D. Xu and J. C. Fyfe Cubilin expression and posttranslational modification in the canine gastrointestinal tract Am J Physiol Gastrointest Liver Physiol, October 1, 2000; 279(4): G748 - G756. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. D. Imig, G. L. Navar, L.-X. Zou, K. C. O'Reilly, P. L. Allen, J. H. Kaysen, T. G. Hammond, and L. G. Navar Renal endosomes contain angiotensin peptides, converting enzyme, and AT1A receptors Am J Physiol Renal Physiol, August 1, 1999; 277(2): F303 - F311. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. J. SALDÍAS, E. LECUONA, A. P. COMELLAS, K. M. RIDGE, and J. I. SZNAJDER Dopamine Restores Lung Ability to Clear Edema in Rats Exposed to Hyperoxia Am. J. Respir. Crit. Care Med., February 1, 1999; 159(2): 626 - 633. [Abstract] [Full Text] |
||||
![]() |
A. M. Bertorello, K. M. Ridge, A. V. Chibalin, A. I. Katz, and J. I. Sznajder Isoproterenol increases Na+-K+-ATPase activity by membrane insertion of alpha -subunits in lung alveolar cells Am J Physiol Lung Cell Mol Physiol, January 1, 1999; 276(1): L20 - L27. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. J. Saldias, A. Comellas, C. Guerrero, K. M. Ridge, D. H. Rutschman, and J. I. Sznajder Time course of active and passive liquid and solute movement in the isolated perfused rat lung model J Appl Physiol, October 1, 1998; 85(4): 1572 - 1577. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Batuman, P. J. Verroust, G. L. Navar, J. H. Kaysen, F. O. Goda, W. C. Campbell, E. Simon, F. Pontillon, M. Lyles, J. Bruno, et al. Myeloma light chains are ligands for cubilin (gp280) Am J Physiol Renal Physiol, August 1, 1998; 275(2): F246 - F254. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Saldias, E. Lecuona, E. Friedman, M. L. Barnard, K. M. Ridge, and J. I. Sznajder Modulation of lung liquid clearance by isoproterenol in rat lungs Am J Physiol Lung Cell Mol Physiol, May 1, 1998; 274(5): L694 - L701. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. V. Chibalin, C. H. Pedemonte, A. I. Katz, E. Feraille, P.-O. Berggren, and A. M. Bertorello Phosphorylation of the Catalyic alpha -Subunit Constitutes a Triggering Signal for Na+,K+-ATPase Endocytosis J. Biol. Chem., April 10, 1998; 273(15): 8814 - 8819. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Dumasius, J. I. Sznajder, Z. S. Azzam, J. Boja, G. M. Mutlu, M. B. Maron, and P. Factor {beta}2-Adrenergic Receptor Overexpression Increases Alveolar Fluid Clearance and Responsiveness to Endogenous Catecholamines in Rats Circ. Res., November 9, 2001; 89(10): 907 - 914. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |