Insights into Glomerular Filtration and Albuminuria

Abstract

To the Editor: In their review article, Benzing and Salant (April 15 issue)¹ suggest that glomerular permselective dysfunction and albumin filtration depend on the decreased ability of podocyte foot processes (effacement) to offer buttressing force to counteract a glomerular transmembrane pressure of 40 mm Hg, with less compression of the glomerular basement membrane. We think that this hypothesis neglects the role of the subpodocyte space surrounding the filtration membrane,² which may increase during pathologic conditions. We recently found in rats that the transmembrane pressure, in the presence of the subpodocyte space, is much lower than the assumed 40 mm Hg, . . .