Isolation by monoclonal antibody of intercalated cells of rabbit kidney

We produced a monoclonal antibody, gamma G6, that reacts only with one cell type in the connecting (CNT) and collecting tubules (CT) of rabbit kidney. The gamma G6 antibody-reactive cells revealed carbonic anhydrase activity, showing one of the characteristics of intercalated (IC) cells. Using immunoelectron microscopy, we demonstrated that IC cells in cortical CT consist of the gamma G6 antibody-reactive and non-reactive cells, whereas all IC cells in medullary CT were reactive with the gamma G6 antibody. We used a cell sorter to enrich this cell type from the isolated kidney cell suspension. When we measured hormone-sensitive adenylate cyclase (ACase) activities of the sorted cells, the presence of parathyroid hormone (PTH) and isoproterenol (ISO) almost doubled ACase activities when compared with the basal values; however, no additive effect of PTH and ISO was observed. They showed no calcitonin-sensitive ACase and negligible arginine vasopressin (AVP)-sensitive ACase. We suggest that the IC cells recognized by the gamma G6 monoclonal antibody possess a receptor(s) for PTH and/or ISO but not for AVP in the CNT and CT, although it remains to be clarified whether the reactivities to PTH and ISO in these cells originate from single or dual cells.