FIG. 3.

Reduced renal accumulation of a fluorophore-conjugated dipeptide (A) and a radiolabeled-dipeptide (B) in Pept2 knockout mice. (A) In kidney slices obtained from wild-type (+/+) mice after intravenous injection of d-Ala-Lys-AMCA, fluorescence was detectable in selected tubular structures of the cortex and outer medulla, whereas in slices from the Pept2 knockout (−/−) mice, only very weak fluorescence was detectable in the outer cortex. Bottom, light microscopy pictures of the corresponding kidney sections. Bar, 80 μm. (B) In kidney homogenates prepared from Pept2 knockout mice (−/−) and wild-type animals (+/+), accumulation of radioactivity after intraperitoneal administration of d-[³H]Phe-Ala was significantly (*, P < 0.05) reduced.