FIGURE 2.

Knock-out of aldehyde reductase was confirmed by measurement of enzyme activity and immunohistochemistry in specific tissues that uniquely express the enzyme as well as by Western blots (not shown) using highly specific antibodies to aldehyde reductase. A shows the GR enzyme activity is absent in the GRKO renal cortex (C) and is reduced to 50% in the GR^+/− heterozygote. Aldehyde reductase is expressed in the proximal convoluted tubules (PCT) of the renal cortex (B) but not in the glomeruli (G) or papilla (P). AR is expressed in the renal papilla (not shown). Note the absence of immunohistochemical staining (horseradish peroxidase staining) in the GRKO renal cortex and proximal convoluted tubules.