title: Controversies in nephrology: response to 'renal albumin handling, facts, and artifacts'.
abstract: For 40 years indirect measurements of the glomerular sieving coefficient of albumin yielded very low values. The first direct measurement by 2-photon microscopy by Russo et al (Kidney Int (2007) 71, 504-513) gives values 50-times higher. This demonstrated that relatively large quantities of albumin are normally filtered based on size selectivity alone. Most of this albumin is retrieved and returned to the blood supply. These new discoveries represent a paradigm shift in our understanding of albumin processing by the kidney. They also serve to explain several anomalous aspects of previous studies on glomerular filtration and mechanism of albuminuria and support the fact that glomerular charge selectivity is not a major factor controlling glomerular permselectivity.
authors.affiliation: Program in Membrane Biology, Renal Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: L M
authors.initials: LM
authors.lastname: Russo
authors.forename: R M
authors.initials: RM
authors.lastname: Sandoval
authors.forename: D
authors.initials: D
authors.lastname: Brown
authors.forename: B A
authors.initials: BA
authors.lastname: Molitoris
authors.forename: W D
authors.initials: WD
authors.lastname: Comper
mesh_terms: D000418:Albumins / Q000378:metabolism* / Q000648:ultrastructure; D000419:Albuminuria / Q000378:metabolism / Q000503:physiopathology; D000818:Animals; D016477:Artifacts; D001665:Binding Sites; D001692:Biological Transport; D005374:Filtration; D005919:Glomerular Filtration Rate; D007668:Kidney / Q000737:chemistry* / Q000502:physiology* / Q000503:physiopathology; D007678:Kidney Glomerulus / Q000502:physiology; D007684:Kidney Tubules / Q000378:metabolism / Q000473:pathology; D007700:Kinetics; D026561:Low Density Lipoprotein Receptor-Related Protein-2 / Q000378:metabolism; D009404:Nephrotic Syndrome / Q000378:metabolism / Q000473:pathology
chemical_list: D000418:Albumins; D026561:Low Density Lipoprotein Receptor-Related Protein-2