The pattern of distribution of selected ATP-sensitive P2 receptor subtypes in normal rat kidney: An immunohistological study

Using immunohistological techniques and available polyclonal antibodies, we have identified several ATP-sensitive P2 receptor subtypes in specific structures of the normal rat kidney. Of the P2 receptor subtypes examined, P2X(1), P2X(2) and P2Y(1) receptors were found in the smooth muscle layer of intrarenal vessels. The P2Y1 receptor was also found on glomerular mesangial cells, the brush border membrane of the proximal straight tubule and on peritubular fibroblasts. In the cortex, P2Y(4) receptors were found on the tubule epithelium of the proximal convoluted tubule, and P2Y(2) receptors on glomerular epithelial cells (podocytes). P2X(4) and P2X(6) receptors were present throughout the renal tubule epithelium from the proximal tubule to the collecting duct. P2X(5) receptors were expressed on medullary collecting duct cells and the apical membrane of the S3 segment of the proximal tubule. Possible functions of these receptor subtypes in normal rat kidney are discussed.