Active synthesis of mouse polymeric immunoglobulin receptor in the epithelial cells of the distal urinary tubule in kidney

The tissue distribution of mouse polymeric immunoglobulin receptor (pIgR) has been demonstrated. By Northern blot hybridization, pIgR mRNA expression was detected in liver, intestine, stomach, lung and kidney. A weak expression was also detected in thymus by reverse transcriptase-polymerase chain reaction. The pIgR expression in kidney was further studied and confirmed that pIgR protein was actively synthesized in the epithelial cells of distal urinary tubule and of Henle's loop. Immunoelectron microscopical analysis showed the accumulation of pIgR-containing vesicles in the apical portion of distal urinary tubule epithelial cells.