Abstract
Using a peroxidase labeled antibody (Fab'-fragments) method, the subcellular localization of dipeptidyl peptidase IV (DPP IV) in rat kidney and small intestine was examined. In the kidney DPP IV immunoreactivity was primarily confined to the brush border membrane of the proximal tubule cells. Immunoreaction product was also detected on the surface of capillary endothelium of the glomeruli and epithelium of Bowman's capsule. In the small intestine, DPP IV was found to be localized on the external surface of the brush border membrane of enterocytes. DPP IV immunoreactivity was also found in the cytoplasmic vesicles, lysosomes and Golgi apparatus in some enterocytes.
The results of the present study confirmed that DPP IV is a brush border membrane peptidase and suggest that in the kidney and small intestine this enzyme may participate in the digestion or reabsorption process of proline-containing peptides.
