ORGAN DISTRIBUTION OF AMINOPEPTIDASE-A AND DIPEPTIDYL PEPTIDASE-IV INNORMAL MICE

The hydrolases aminopeptidase A and dipeptidyl peptidase IV both prese nt in the kidney on the brush borders of the proximal tubule epithelia l cells and podocytes, are involved in the induction of experimental m embranous glomerulonephritis in the mouse. However, little is known ab out their (co)distribution in other tissues and their function in heal th and disease, A detailed insight into the localization of these two enzymes is a prerequisite to elucidation of their function. Therefore, wt investigated the presence and co-distribution of aminopeptidase A and dipeptidyl peptidase IV by immunohistology with two different rat monoclonal antibodies, the specificity of which was determined by an i mmunodepletion technique. In addition, the molecular weight of the hyd rolases was analyzed by SDS-PAGE after isolation by solid-phase immuno precipitation from glomeruli, renal brush borders, and thymus, Both hy drolases showed different molecular weights in renal corpuscle, renal brush borders, and thymic tells. A widespread organ distribution of th e two hydrolases was observed, with co-localization in kidney, liver, small intestine, thymus, brain, spleen, and lymph nodes, either on the same cells or on different cells in the same organ. This distribution and partial co-localization suggests that the two hydrolases, acting either alone or in concert, have a role in many diverse biological pro cesses.