Under physiologic conditions, significant amounts of plasma protein pass the renal filter and
are reabsorbed by proximal tubular cells, but it is not clear whether the endocytosed protein,
particularly albumin, is degraded in lysosomes or returned to the circulatory system intact. To
resolve this question, a transgenic mouse with podocyte-specific expression of doxycycline-
inducible tagged murine albumin was developed. To assess potential glomerular
backfiltration, two types of albumin with different charges were expressed. On administration …