Megalin/gp330 mediates uptake of albumin in renal proximal
tubule.
Cui, Shiying, Pierre J. Verroust, S[stod]oren K. Moestrup, and Erik
Ils[stod]o Christensen.
Department of Cell Biology, Institute of Anatomy, University of
Aarhus, DK-8000 Aarhus C, Denmark; Institut National de la
Sant[acute]e et de la Recherche M[acute]edicale U64,
H[circumflex]opital Tenon, Paris, France; Institute of Medical
Biochemistry, University of Aarhus, DK-8000 Aarhus C, Denmark
APStracts 3:0126F, 1996.
Serum albumin filtered in renal glomeruli is reabsorbed very
efficiently in the proximal tubule by endocytosis. The present study
was undertaken to determine whether megalin/gp330 binds and mediates
endocytosis of albumin. Rat serum albumin (RSA) labeled with 125I and
colloidal gold particles labeled with bovine serum albumin (BSA) were
microinfused into rat surface proximal tubules in vivo and tubular
uptake was determined in the presence or absence of different
substances known to interfere with ligand binding to megalin. Binding
of 125I-BSA and 125I-RSA to purified megalin was also determined
directly using Sepharose columns.
Received 1 March 1996; accepted in final form 11 July 1996.
APS Manuscript Number F74-6.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 25 July 1996