HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/3/H1371    most recent 01364.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Rosengren, B.-I. Articles by Rippe, B. Search for Related Content PubMed PubMed Citation Articles by Rosengren, B.-I. Articles by Rippe, B.

Transvascular protein transport in mice lacking endothelial caveolae

Departments of ¹Nephrology and ²Experimental Medical Sciences, Lund University, Lund, Sweden; and ³Department of Biomedicine, Section of Physiology, University of Bergen, Bergen, Norway

Submitted 23 December 2005 ; accepted in final form 24 February 2006

Caveolae are -shaped vesicular structures postulated to play a role in transvascular protein transport. Studies on mice lacking endothelial caveolae, caveolin-1 knockout (Cav-1-KO) mice, indicate increased macromolecular transport rates. This was postulated to be due to the appearance of an alternative pathway. The present study tested whether an alternative pathway had appeared in Cav-1-KO mice. Male Cav-1-KO (n = 12) and male control mice (n = 13) were intubated and anesthetized using 2% isoflurane. ¹²⁵I-labeled albumin, ¹³¹I-labeled immunoglobulin M (IgM), and polydisperse FITC-Ficoll were administered intravenously. During tracer administration, a 90-min peritoneal dialysis dwell was performed. Clearance of tracers to dialysate and permeability-surface area product for glucose were assessed. Transvascular protein transport was higher in Cav-1-KO compared with control mice. Albumin clearance from plasma to peritoneum was 0.088 ± 0.008 µl/min in control and 0.179 ± 0.012 µl/min in Cav-1-KO (P = 0.001) mice. IgM clearance was 0.049 ± 0.003 and 0.083 ± 0.010 µl/min in control and Cav-1-KO mice, respectively (P = 0.016). Ficoll clearance was increased in Cav-1-KO mice. In conclusion, the lack of caveolae in Cav-1-KO mice resulted in a marked increase in macromolecular transport. A two-pore analysis of the Ficoll clearance data revealed that the higher transport rate in Cav-1-KO mice was not compatible with the appearance of an alternative pathway for macromolecular transport. In contrast, the higher transperitoneal protein and Ficoll clearance is consistent with passive porous transport through an unperturbed two-pore system, presumably at an elevated capillary hydraulic pressure. Alternatively, the data may be explained by reductions in the selectivity of the endothelial glycocalyx, leading to an increased capillary hydraulic conductivity and large solute filtration.

permeability; pores; transcytosis; vesicles; macromolecules

This article has been cited by other articles:

				B. Rippe Free water transport, small pore transport and the osmotic pressure gradient three-pore model of peritoneal transport Nephrol. Dial. Transplant., July 1, 2008; 23(7): 2147 - 2153. [Full Text] [PDF]

				S. A. Predescu, D. N. Predescu, and A. B. Malik Molecular determinants of endothelial transcytosis and their role in endothelial permeability Am J Physiol Lung Cell Mol Physiol, October 1, 2007; 293(4): L823 - L842. [Abstract] [Full Text] [PDF]

				S. Albinsson, Y. Shakirova, A. Rippe, M. Baumgarten, B.-I. Rosengren, C. Rippe, R. Hallmann, P. Hellstrand, B. Rippe, and K. Sward Arterial remodeling and plasma volume expansion in caveolin-1-deficient mice Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R1222 - R1231. [Abstract] [Full Text] [PDF]